I'd love to see how fast my Android phone runs with 2.2. Too bad I can't. One thing the iOS releases have going for them is that users can actually get them when they are released. 48 Days later, I still don't have the 2.2 update.
Wiki is wrong, then. The official 2.2 update for the Nexus One only went out about a week ago, and Froyo code was added to AOSP about a week before that.
I installed Ultimate Droid Froyo on my Motorola Droid, and I saw an enormous speed improvement over 2.1, so I think there will be a pretty significant difference.