…on the eve of the official announcement of dev.live.com. First off, a new SDK (software development kit) has surfaced at dev.live.com and MSDN, the
Messenger Add-In SDK – beta. Unfortunately, the two available sdk's for Messenger are listed in two places in the MSDN Library, and the Add-In SDK isn't listed under Messenger SDKs at dev.live.com, you have to find it by clicking on "Learn More". Hopefully dev.live.com will get this straightened out soon, as the new site can be quite helpful in navigating through MSDN in search of Windows Live development tools.
In addition, Expo has also recently released an API. It's on dev.live.com, and Dare talks about it here. Omar's team talks about new APIs coming for Windows Live Mail on their new Channel 9 interview, and the Windows Live Mobile team is opening up their platform to development as well. We'll have more on WL Mobile soon.