Google is apparently close to unveiling its phone platform within the next two weeks, but still has the considerable hurdle of convincing carriers to sign over some of the control of the phone itself.
While Google will provide many of the services which will come on the phone -- such as its search, Maps, YouTube, and Gmail services -- the platform on which those applications are built will be completely open, right down to the operating system itself. This is a dramatic shift from what is available currently. Most carriers and phone manufacturers lock most of the code down, making it relatively difficult to build new applications without either deals with the carriers or manufacturers themselves.
Only Microsoft offers anything close to what Google is going to do, through Windows Mobile. It took Apple some four months after it released the iPhone to finally agree to open up the device to third parties, and other manufacturers and carriers offer even more limited third-party support.