I play both games. From what I see Rift is doing way better than Blizzard would ever like to admit. I bought MoP and started focusing on it. I feel a bit let down. Talent tree's are a joke now. CRZ pretty much ruined my server. I hate the huge wall of Dailies to be done.... On the other Hand Rift is still a young game. It has it's failings as well. I know it is a bit of a WoW clone, however A LOT of people I know stopped playing WoW for Rift. IDK let me hear some opinions. No insults please. Just opinions on both games. If you haven't played either game, please don't reply.
WoW is stale for a lot of people, me being one of them. Regardless of that, it does a lot of things right. You also don't have to do those dailies to progress, but they're a time filler to make you think there's more to do. Raiding would be the only reason I play WoW, and it's not enough to justify paying 15/month to raid twice a week.
Rift's combat always felt stiff and poorly done to me. I love the world events in Rift, but I could never force myself back into it because of how awful the combat is.
I finally grabbed GW2, and EvE online as my mmos of choice because of how much I flip flop. No sub fees is really nice for GW2. And I have no issue making isk, the currency of EvE, to buy plex's to keep my sub up. Even only playing a few days a month.