I'm using .9RC4 right now, it's great. The only problem is that the flash exporter doesn't seem to be working with Firefox 3.5RC1, but that's a Firefox bug so who knows when it'll get fixed. It worked fine until this week, and it still works in Safari and every other browser :-/

If you want to see an example map check out http://www.alexkrupp.com/earth.html

The only caveat is that some of the default appearance preferences are a little wonky in the .9 release. I'd recommend turning on full antialiasing, and checking the box that says "Edges start from one point at root node." (And turning off the text editing box at the bottom unless you are going to use it.)