Well, I don't really understand this whole "evolving/revolutionizing the MMO genre".
For me, it looks more like "
extending the MMO genre" because GW2 will offer different options to player alongside WoW and SWTOR.
(for example, no dedicated healer can be as much a pro as a con depending on people).
It's not as if there should be only ONE way to do a MMO, be it the WoW way, the GW2 way or the SWTOR way.
So 2012 looks like the year where the MMO genre will finally get good options for players to choose from.
Some will play just one, some will play many.
So to answer your question, GW2 will be successful while being quite different because I think it will find its very own audience.
And this is coming from someone that don't intend to play the game
(I love raiding and healing in MMO, so no luck for me with GW2
)