If you've been using the Windows Live Tools for Visual Studio, the February 2008 CTP has been released. See the notes here: https://connect.microsoft.com/content/content.aspx?ContentID=7901&SiteID=505&wa=wsignin1.0
So what's different?
Messenger Chat Control has been added
Depenency on ASP.Net 3.5 Extensions has been REMOVED.
CTP is compatible with Silverlight 2.0 SDK
The site is context sensitive so click on Downloads to get the list of builds available for download or go here: https://connect.microsoft.com/Downloads/Downloads.aspx?SiteID=505