The newest video from Rift: Planes of Telara is the most interesting yet. It shows an area of the gameworld as it normally exists, and then again as it appears under the influence of some of the different rifts. I still think the animation and models look blocky and artificial, but this footage is actually pretty neat.
I’m torn on whether or not preset configurations to the world really qualifies as anything more “dynamic” than the similar effects we already see in WoW, Guild Wars and LotRO. It depends on how it actually feels in play, I suppose. So we won’t know for a bit yet.