After begging and pleading and doing everything short of selling my soul, I got an invitation to Popfly, Microsoft’s Silverlight (there I said it) based programming tool. I believe it is the result of the "Tuscany" Project. Since it is tangentially WPF related, (not only does it use WPF/E; Adam Nathan, author of WPF Unleashed, was a developer) it’s fair game here!
Using Popfly, I was able to create a mashup between twitter and Virtual Earth in minutes. And I don’t do mashups. Anyway, it looks very promising, I’ll let you know more about what I think later. (Looks like Nathan Dunlap has received his invite too!)