MSN's Answer to Google and Yahoo!'s dynamic Web-based mapping tools, Virtual Earth, went live this morning. Needless to say it works better with IE than Firefox (the browser I typically use). It doesn't have the "wow factor" of Google Earth, which is a client-side application — that's really an apples-to-oranges comparison. However, it does have some nice features (e.g., "scratch pad," saved locations, map size, proximity/layered searches), which I haven't had time to fully explore.
It's definitely a welcome addition to MSN's local search capabilities. Intensifying mapping competition — MSN told me they will have an API too — will mean further innovations for consumers going forward. I'll play around with it more and write more later.