ESO just went into early release yesterday. The official release is later this week, and anyone who grabs the 'pre-order' this week can get in right away.
I bought it, so I'm in. But I probably won't play it for a while. I'll let it mature first, since almost every MMORPG out there has needed a year or two to mature.
I logged in yesterday just to get a character started, and the main thing I noticed is that the starting zones have been changed. As in, you don't start in the same zones as in the beta. Now everyone starts at the faction capitol cities, and the previous starting zones have been turned into regular questing zones. People complained in the beta that the beginning of the game felt too linear, so they changed it.