I have tested it, it works fine. Another user reported some minor glitch while editing XAML source (the cursor moves one cell if you Alt-Tab to another app and back), I will be looking into it, but else it should be no problem.
I posted about this the day after VS2008 RTM was released, in the new ViEmu-specific blog:
http://www.viemu.com/blog/
I will have to sprinkle a few links to this blog here and there and notify all current customers by email, so that nobody misses it. It will be a good place for news & announcements.
Regards,
- Jon