Windows Live Local beta released yesterday
Windows Live Local was released in Beta yesterday. This gives the 45-degree view, as well as some nice features over Google Maps. It's not a full replacement; Google Maps for example includes some landmark information; check for example Software Answers, which shows Bicentennial Park and Rose Hill Cemetary. Both are missing from the same view on Windows Live Local.
That said, if bird's eye view exists for a site (like it does for my house), it's very, very cool. Check out SF for example: http://local.live.com/default.aspx?v=2&ss=10%20market%20st%20san%20francisco~10%20market%20st%2c%20san%20francisco&cp=37.796319~-122.397896&style=o&lvl=1&scene=1155891&sp=adr.10%20Market%20St%2c%20San%20Francisco%2c%20CA%2094111 . Very nice.