We've got talent previews for four classes for cataclysm at this point. As a priest there is a lot to be excited about. As a resto shaman there is nothing to be excited about. In fact, the attitude of a resto shaman I know was closer to "pissed" than "excited." Not only are there virtually no changes to the tree, but some changes that we pretty much received specific promises about didn't happen. There is still a talent for 5 points that is worth 2% extra healing per point.
Discipline Priests have 5 new talents, 6 talents moved around between tiers and quite a few substantial changes to the way they work. I tried to make a discipline build and if their goal was to give me interesting choices and to create a "cookie cutter" talent build that left 10 to 15 points left over to spend how I want then they were successful. They were probably even more successful at this in holy where I can see many different ways to spend my last 10-or-so points. In the resto shaman tree there two new talents, one talent has been removed and everything else is exactly the same as it was. My attempt as a resto shaman build left me feeling like there were very few places to spend my points, and ended up looking almost exactly like a current resto shaman build.
From Purification and Nature's Blessing I hope I can assume this tree is far from finished. Seems like they should have previewed three classes instead of two; there might be a lot fewer worried resto shamans out there right now.