Released yesterday, Visual Studio 2010 SP1 (availble to non MSDN subscribers on the 10th), offers some great new features for front end developers, as well as a few let downs. 

For me the best feature is IIS Express support, meaning you can set the local hosting server as IIS Express instead of Cassini. Amongst other things this allows you to add MIME Types for all these new file types like, er, 1999s .svg as well as actual new formats like .ogg and WOFF. 

There is an HTML5 (and XHTML5) schema offering a better set of elements than previous unofficial schemas. The HTML5 element support is pretty good. At least until you get into the finer details. 

Adding <input type="email" runat="server" /> throws a Parser Error that 'email is not a valid type for an input tag'. Where <asp:TextBox ID="TextBox1" type="email" runat="server" /> 
serves up <input type="text"> instead of type="email" (Feedback/bug filed at Microsoft Connect).

The validator also wrongly requires the type attribute on script elements, which is optional in the HTML5 spec. 

With CSS there's a distinct lack of an CSS3 schema, the release notes mentioned that 'there are [only] a few improvements in the CSS3 support ... though not as elaborate as with HTML5.' Which equates to nth-child, first-child and rgba colours being ok but most of everything else, from @font-face and border-radius to opacity and text-shadow still showing as invalid. 

All in all, a good start for front end support by Microsoft for their IDE but definately some room for improvement.