I can't remember if I first tried Unity in 10.10 or 11.04, but back then I thought it was a candidate for the worst UI ever perpetrated on humanity. I tried it again in 11.10 and found it was vastly improved, to the point where I found it very usable, and now I'm productive with it than I was with Gnome 2. I expect the 12.04 version will be still more polished.
No announcement yet.
Ubuntu 12.04 LTS "Precise Pangolin" Released