From the blog: http://blogs.msdn.com/sharepoint/
The Visual Studio extensions for SharePoint (VSeWSS) provide project templates for developers using Visual Studio 2008 to create, debug, package and deploy SharePoint projects including Web Parts, Data Lists, Content Types, Event Receivers, Templates, Modules and other SharePoint artifacts. The v1.3 release is an incremental release of the VSeWSS including top feature requests. It is an interim release for SharePoint Developers on the roadmap until Visual Studio 2010 is released with significantly improved SharePoint development tools as outlined here.
The Community Technology Preview (CTP) release is available here on Microsoft Connect where customers can also report any feedback they have. It is anticipated that all existing VSeWSS 1.2 projects will work with the CTP. The CTP is not supported by Microsoft Customer Support Services. You are encouraged to provide feedback through the Microsoft Connect site and to discuss the extensions on the SharePoint Development MSDN Forum.