The thing is that we could probably keep the old map, honestly, and just update to the latest version, I think.
The problem is we won't get some of the new content, they've added some new natural blocks and have also redone a bit of the world generation. I also think that, it's been a year, so might as well start a new? Big structures are cool and all but once you've made them that's sort of it. I'll definitely save the old map and make it available for anyone to download to marvel at, but as far as keeping the old map for the entire server... don't you think it's time to start anew?