Android 3.0 Honeycomb Smartphone Support Hinted
The next Smartphone version isexpected to launch in the next 4 to 5 months(Ice Cream Sandwich). This new version is expected to fall in the 2.X version.
It has been found in the Android 3.0 SDK though which hints at 3.0 also being compatible with smartphones. The emulator used in the SDK can actually be set to a lower resolution to match a smartphone screen sized resolution.
it appears that Google might in the future, look at the option of keeping the same Android version on both tablets and smartphones in a way similar to how iOS 4.2 works on the iPad and iPhones.
it wont cause too much problems, if any at all, as Google will likely use similar features between both versions.