I'm decidedly more on the apprehension side of the fence.
I use gnome these days, mostly because of the KDE debacle which, despite the new versions, still has a way to go. I'm not keen on a repeat.
Really, they have spent years polishing gnome into a usable desktop. Everyone is just settling down with it and getting happy. But because the gnome developers are bored, they are going to embark on a half-baked attempt to make the next big thing in desktop technology, and the users/distros will end up paying for it.
I'm not saying that they shouldn't give these new ideas a go, but what makes me nervous is that it's Gnome 3.0, not Gnome: Experimental Horrors Edition. 3.0 gives me the sense that this will become the new One True Way of the Desktop, almost by default, good idea or no.
It also works against their stated goals to some degree. Gnome, in addition to being a political response to KDE, was designed to make things friendly and easy to use for normal, non-technical users. For the most part, they have succeeded. I think it does that constituency a disservice to completely re-conceive the desktop every so often, particularly if it's not being done in response to actual user needs.
The larger computing community are past the point of sudden radical shifts in thinking. Otherwise we'd all be using MALTRON or DVORAK keyboards. Experimental and radical ideas are great in projects not aimed toward the mainstream, but any changes to the default, non-technical person's environment needs to evolve slowly over time so that our less technically inclined brethren can keep up and keep working.