Android is unquestionably the dominant OS in the US, and gaining quickly worldwide. Open platforms and multiple hardware vendors once again trounce the locked-in/single-source approach.
I’ll go out on the limb with a few predicitons:
(1) Android will dominate the smart phone market with Apple a strong second (like we see in personal computers).
(2) The iPad will be overtaken by a Android pads in poplularity in a year.
(3) TV centric internet devices (like Roku and upcomming Boxee device) will grow quickly over the next 5 years. These are currently Linux based, but open Anroid devices will come to dominate this area giving Google one more area it dominates.