Perhaps the new foe will be Whis? Afterall he's considerably more powerful than billis even though billis is considerably more powerful than even Goku.
Yeah, so from what I've gathered AT is going to resurrect the series, he's showed interest in the idea without publicly saying it, saying that he wishes to continue the saga in his own direction. Unfortunately, for me at least, this would make GT non-cannon officially, while there's a whole lot of debate whether GT is cannon or non-cannon there is still no real consensus, AT has publicly said that he supported the show and even worked on a few of the designs, contrary to popular believe he never directly said GT was non-cannon. And while everyone seems to hate GT, I thought it was good, not as good as Z but still good, a nice end to the series. Making it non-cannon just confuses the hell out me, I've had a hard enough time getting by the movies not being cannon, but having an entire series of some 80 episodes watched and be told it all didn't matter doesn't sit well with me personally.
But then again, more DBZ! Nothing can be wrong with more DBZ, with the new movies showing, like Vegeta's cousin coming to earth and now Battle of Gods (it become released in English which was a huge surprise for me) and this new BoT movie, perhaps a new series is on the rise, the God Saga.
Whiss will not be the villain, the one being resurrected will be. That has pretty much been hinted at by the teaser trailer with the whole "Despair" caption.
GT is non canon, there is no real debate about it and the consensus is that it is non canon because it is. Any DB forum you go to, most DB sites, etc... you will find the majority state that it is non canon. That is a consensus. Consensus doesn't mean 100% agreement, it means majority agreement. The small percentage of people who try claiming it as canon are simply not educated on the concept of what canon is. GT is an official side story, but official =/= canon. AT's support =/= canon, and it having 64 episodes as a series does not make it canon.
Canon = material created directly by the original creator/author
unless otherwise stated by the author. AT never said it was non canon, because he doesn't have to in order for fans to know it's not. He also never stated it was canon thus it is clearly non canon. Even when things are canon he doesn't directly spell it out and say "This is canon, this is canon, this is non canon" etc... because the definition of canon already tells you what is canon and what is not. By the definition of canon we can then come to the conclusion that the only things canon to DB are the manga, Bog, and this new sequel, as he had direct creative control over all of them. Creating basic character deigns and giving a few tips to Toei does not make it canon because in the end, Toei had creative control over the entire thing, not AT himself. So that is what makes the 13 movies and GT non canon.
Now, you may get a lil' confused however, as there are different kinds of canon. The 13 movies and GT are indeed non canon as far as AT's works go. But GT is considered a canon work of Toei. Just as the DB/Z anime's are canon to both AT and Toei. Confused? Well this is what I mean... All of the stuff in the anime that is also in the manga would be canon material from AT taken from his manga. However, all of the non canon filler in the anime that Toei threw into the anime to fill time (I.E. why the term filler is called filler) between manga chapters because the anime was right on AT's heels as he made each new manga issue, is non canon to the manga, but is canon to Toei. Examples of this would be Nappa and Vgeta going to Arlia and fighting those insect looking aliens on the way to Earth, when Vegeta had the brown hair and greenish looking armor. The reason Vegeta had that color scheme in said filler is because Toei did not yet know the true color scheme for Vegeta yet through AT's manga because AT had yet to color an image of Vegeta yet. Another example of filler would be Goku and Picolo learning to drive cars, and Krillin fighting Imperfect Cell, saving that woman and her kid at that airport, etc... etc... the anime is filled with countless filler, way too much to list in this post. The entire Garlic Jr. Arc is non canon filler, thus is in the same league as the entirety of GT, only GT isn't filler it is just an entire non canon series as far as AT's works are concerned. Non canon isn't always filler but all filler is always non canon.
However, why should you allow that to bother you anyway? Honestly, who cares if it is non canon or not? That shouldn't make a difference to whether or not you enjoy it for what it is, a piece of media entertainment fiction, right? So I don't think you should let such a silly thing bother you in the regard. Whether or not it is liked or hated by so many doesn't have to do with it being non canon so much as Toei just has a way of really screwing things up in a way AT never did. AT has screwed some things up in his own works as well, but compared to Toei, not nearly as bad consistency wise. Toei just made a real mess out of most of the 13 movies and GT, but that is not to say many DB fans didn't enjoy them despite the mistakes and inconsistencies. I liked most of the 13 movies and as I said earlier, I enjoyed the Bebi Vegeta and SA17 ars in GT despite their major issues. They were still entertaining and enjoyable for the most part.
As far as AT ignoring GT and it's events for these films and even when he helped create Dragon Ball Online, doesn't necessarily halt the officialness or his support of GT within the DB franchise overall. He is simply just ignoring it because it is not his own work, and he acknowledges it as a side story, not a direct canon continuation of DBZ. It is however, still a part of DB in general as an official side story continuation of DBZ. I know that may sound confusing, but that's how it is.
If it helps, just look at the 13 movies and GT as alternate timelines, similar to how Future Trunks had his own timeline that differed from the one we all know of. If you look at them as different timelines and alternate realities within the DB universe, then their mistakes, contradictions, and inconsistencies when compared to the "canon timeline" aren't that big of an issue in that context.
With starting a new series, I am not so sure that is the way AT wants to go. I think he is more or less just interested in making full length feature movies, not a whole new series. There are all kinds of rumors floating around about how he wants to make a new series, and another that says he wants to make this movie series a trilogy meaning there will be another final movie made after this one. All however, are just rumors as of now, and nothing has been officially stated by AT, so we pretty much have to wait and see, but in my personal opinion I don't think AT is interested in doing another full fledged series. DB is just too old, and he has moved past it more or less. These BoG movies are an exception it seems, as in the past up until these movies were made, he didn't seem interested in further pursuing another series. Perhaps his mind has changed? Who knows, but from what I have seen over the last decade+ he never seemed all that interested in revitalizing an old series of his from 25 years ago in a new series format. Movies maybe, but a whole new series is yet unknown. Not to mention he is very forgetful and has let a lot of things from it slip his mind, so if he were to make a new series, he would either need to remind himself of his past manga facts, or just wing it and make it his way in modern times, which is more or less what he is doing with the movies I suppose.
There is no word of the movie being dubbed in English as far as I know. Where did you hear that from? It is being released on DVD in Japan, but no confirmation of it being dubbed in English and released by Funimation in America. Maybe that's where the confusion came from? They have yet to dub and release older projects in English yet, such as the 25th anniversary special with Vegeta's brother (not cousin) Table, or the SSJ Bardock special with Lord Chilled. I would like to think they'd dub those before the movie, but the movie did go to theaters in Japan so it is possible they would dub it before the other two specials, but I do not think there has been an announcement of that yet.