Minimum RequirementsAccording to the reports, Gingerbread could require at least a 1GHz processor, 3.5 inch display, and 512 MB of RAM. Most phones will upgrade to 2.1 or 2.2 while these versions become the standard baseline for awhile. 1280 x 760 resolution will be supported for screens larger than 4 inches, which means that tablets are a likely candidate for Android 3.0 installations. However, future smartphones will probably run 3.0 as well. Some Gingerbread-running models could have up to a 4.3 inch display and a dual core 800 MHz processor (HTC Vision) or even a 2GH processor (coming from Motorola).
Another tablet clue is Intel's recent involvement with an x86 port of the platform. However, this could just be because Google TV's Android will run on Atom-based set-top boxes, but tablets could also be Atom-based.
The UIBack in June Google said they were "laser focused" on revamping the UI so that third party layers like HTC's Sense or Motorola's Blur will not be necessary. Android also wants to make its UI as popular, and user friendly as Apple's
The leaks indicate that Google may be slowing down its OS development cycles to Apple-levels as well. Constant battles with fragmentation could be the reason why Google might keep maintaining Android 2.1 and 2.2 in parallel with 3.0 for awhile.
Update: Open Source and Compatibility Tech Lead Dan Morrill responded to the reports on Twitter. Neither confirming, nor denying he said: "In summary, please remember that rumors are not official announcements. ;)".