I haven't been posting about product releases lately (other than aggiorno of course) as I've been trying to focus my posts on more concrete yet ideation-like process, still I think I see this as a public service given that no official announcement has been made.
From the page we can read:
SP1 addresses issues that were found through a combination of customer and partner feedback, as well as internal testing. These service packs offer Visual Studio and .NET Framework users improvements in responsiveness, stability and performance.
Even though this service release does address a bunch on issues from the current release, it also adds a lot of new functionality specially for the ASP.NET and WPF set of APIs.
Links to downloads are:
Hope you guys have fun with these new releases and let your brain and skills go nuts with the pack of all new features.
Update: check out the official post on the release at Soma's Blog.