As a muslim, I will say that this is an excellent event and idea... will it make a significant impact upon the opinions of muslims that is held by over half of the US population?... No. I dont think it will. Events like this have come and gone in the USA, in Britain, in Germany, all over the place. They help a bit and do change the minds of quite a few people, but the people who are actively against Islam will most likely not be affected by this.
That said, there's always a good thing inherent to hope.