Ok...I was bored, so I started playing with the Google Maps API and the MCE SDK. The result was this page : http://savage.org.za/GMAPMCE/ which doesn't really add much functionality other than being able to browse the world from your couch with the remote.
To add to your Media Center simply download and install GMAPMCE from the links on the right and it's available to use in Windows Media Center under the More Programs menu.
On the web page use the arrow keys to move around and PgUp / PgDn to zoom. On MCE use the arrow buttons and CH [+][-] on the remote.