Grats ESO on what is turning out to be a great addition to the MMORPG realm! Being a recent fan of ES I was very happy to hear of the game taking the natural next step in going MMORPG! Your decision on the monthly subscription model shows your serious commitment to a sustainable and terrific game.
My concerns about end game specifically revolve around raids and gear progression. Following are my opinion on three MMORPG's that I have extensive end game experience with including world rated WoW and Rift raiding. If you have other examples for or against my view point please point them out for further discussion.
Failed end game model:
GW2 "raids" are extremely easy and no progressive rewards given.
Successful end game model:
WoW raids vary in challenge and give great progressive rewards.
Semi successful end game model:
Rift raids vary in challenge and give decent progressive rewards.
One problem with raids in MMORPG's is that it often involves so much complexity that only a few people could be considered raid worthy. There may be a middle ground that allows for some success with random pick up groups I am hoping that GW2 will find that happy ground.
I am perfectly happy with waiting a few months after release to get these raids but I feel for the longevity of the game they are essential.
Thanks!