Microsoft's Virtual Earth is live. Here are two shots of where I grew up. One from Virtual Earth, the other from Google Maps. The image from Virtual Earth aerial photo is at least ten years old (I'd guess up to 15 years) as it shows the home that I grew up in. A year before I moved out my parents had a new house built, installed a pool, and completely relandscaped. The Google Maps satellite photo was taken within the last nine months as it shows my folks new black pick up truck and their new fifth wheel trailer. Google wins on image quality and up to date images.
Furthermore, I use Firefox. I've never had any problems using Google Maps. With Virtual Earth, within five minutes I had seen at least two "You gotta have Internet Explorer" messages that were blocking me out of what otherwise sounded like cool features of the site. They're not cool features any more. To me they're bugs. Bad bugs. Bugs that make me say to Virtual Earth, "I'm not coming back to use your service any more. I'm going to stick with Google Maps."
Virtual Earth vs. Google Maps