Hopefully 2.0.1 addresses some of the many iPhone ills that have been plaguing users of 2.0.0 and that it's not just a cat-and-mouse release to foil the unlockers and jailbreakers.
I will update the story as details flow in. If you've installed it, please post your observations in the TalkBack below.
Update: Twitter-ers are reporting that 2.0.1 appear to be faster than 2.0.0 (my iPhone is still backing up). John Gruber notes that "the UI, system-wide, is snappier — typing, animations, launching apps."
Update 2: The Pwnage Tool doesn't work with 2.0.1.
Update 3: Flipping between applications on the home screen is much faster and smoother, Contacts appears to be much faster, especially when clicking on the alphabet bookmarks. Sync is definitely faster, but Backup doesn't appear to be any faster.
Update 4: Headline changed from "dropped" to "released" due to the minor panic/misunderstanding that ensued in the TalkBack.