Wow. I am totally blown away by Biztalk Services. Simply put, it is an ESB in the cloud. This is still early CTP quality, but worth learning about. I think that this could represent the future of web services and application development. It has the potential to change the game in terms of application development and integration across organization boundaries.
Here is the channel 9 video" with John Shewchuk and Dennis Pilarinos. John is a Microsoft Distinguished Engineer and the lead for this effort. Dennis shows off some awesome demos. The video is a must-see.
You can learn more and download the SDK from labs.biztalk.net. It took me only 10 minutes to download and install the SDK, register, and have the first sample application running live.