"Holy trinity" or not, all games make that claim :x
WoW has like ... what? 33 viable talent trees now, each with different potential specs within now?
EQ and similar games go way beyond that.
You will find however that only very few of those specs are 'truly' viable if you want to be 'world competitive'. No matter what a game claims in it's diversity there will always be a most optimum set up.
So, while I applaud GW2 for trying to do something ....well can't even say new, because other games have done it, but making a point of saying it's different. They are more than likely going to end up with the same deal as every other MMO.
Certain stats will be better than others, certain talents will be better than others, certain classes will be better than others.
Those who want to push the game as hard as they can as fast as they can will do a lot of math to work out which those are, and use them exclusively, and anyone who uses anything else will be 'lesser players' or 'casuals' or 'noobs'.
I'm not saying GW2 is going to be bad, I'm not even saying it's going to be exactly the same as every other MMO, I'm just saying, ya know, based on the track record, even for games that have desperately tried not to become this, it will be like this, in some way shape or form.
So, try not to buy into the marketing.