I played some Rift beta. It essentially felt exactly like WoW to me, and I never stayed interested at all.
As of yesterday, they added level 50 versions of all the "dungeons" you can do leveling up, 2 operations (raids), and a bunch more content is supposedly coming for release, so that's pretty good. And the dungeons are 4 char groups, while operations are currently 8 chars. So it'll be easier to find groups and raids. In addition, with all the dungeons I ran over the weekend, it feels like, at least in the leveling dungeon, that loot drops based on the classes you have in the group, so you don't get garbage blasters if you have a group with 4 jedi, or something like that. Then you're able to remove the mods from weapons and place them in other weapons, which is going to make operation loot less rotty too.
I have some pretty high hopes so far, even though there seems to be way less hype than Rift had.