From the download page:
This CTP is an update to July 2008 CTP Release. In this CTP, we have made Windows Live Tools compatible with Windows Azure and upgraded to Silverlight 2.0. This package includes following:
ASP.NET Server Controls
Visual Studio Project Template
• ASP.NET Windows Live Web Site
• Windows Live Web Application
• Windows Live Web Role (template for Windows Azure Cloud Project)
The update, from what I can tell, will require you to uninstall any previous version of the Tools (although this could have just been my PC, but whatever).