Guess when you consider buying the satio the camera is really important for you. Unfortunately the cameras of almost all android phones are crappy, except maybe the SE X10. The N900 camera sucks too.

In your case Id wait for the nokia N8. Symbian3 looks quite promising, the structure of the UI may be the same, but if the GUI is really hardware accelerated is should be really smooth (better than android and maemo). But it will be a multimedia handset, web browsing experience will not be stellar with those specs.

Cheers