Installed it on my 1G Touch. Didn't see any significant difference. Backing up speed is around the same as 2.02, still kinda slow. 1 nice addition is the podcast section. Before, the UI only shows blue dot for unheard podcast, and nothing whether you done listening to the podcast or halfway through it. Now, it shows a half-blue-half-white dot for unfinished podcast. Great update, especially for those that listen to a lot of podcasts.
I couldn't care less about the "Genius" feature. Plus, you have to enable it in iTunes first. If not, the "Genius" on the Touch is disabled. On the keynote, Jobs made it sound like the Genius on the Touch is independent of iTunes, but missed this specific detail.