The first credible rumors about Android 3.0 have just broken. Eldar Murtazin of Mobile-review spoke about his knowledge of the upcoming OS in a Russian podcast. The folks at Unwired View transcribed the audio and have some rough details for us.
Expect 3.0 to go live in mid-October, around the 15th or 16th. It will require a minimum 1 GHz processor, plus 512 MB of RAM and a display of over 3.5". A new 1280x760 resolution will be available for larger Android phones and tablets. The user-interface has been "completely" redone, and 3.0 officially represents the divide between high-end and low-end Android devices.
Lesser phones and tablets will use 2.2/2.1 or some appended version of that, while bleeding-edge phones, tablets and netbooks will continue up from 3.0.