Hmm, I think they are more polished. The graphics engine is much better in Rift (same as Warhammer). In order to do the quests, I haven't had to look at sites like WoWHead, all the necessary hints are built into the UI. Those kinds of refinements go on and on. I can't believe this is a "new" game. The level of polish and stability is amazing to me.
If you play Rift just gently, you'll think, "man, this is a total WoW rip." However, it takes a bit of time to see how they are so different. I asked that question to my WoW God-Friend, and he definitively stated they two only look similar. If you stop and think a bit about it, WoW is a rip of EQ2 which was a rip of DAoC which was a rip of EQ1 which was a rip of UO. Frankly, Rift is a great blending of the best parts of all the games so far. You just have to give it 20 levels to start really seeing the differences clearly.
My friends are having a ball in the PvP area; they are actually dragging me into it tonight. Will be the first time I've PvPed in a 1st person MMORPG. This should be interesting...