In case you missed it, Visual Studio 2008 SP1 Beta has been released:
http://www.microsoft.com/downloads/details.aspx?familyid=CF99C752-1391-4BC3-BABC-86BC0B9E8E5A&displaylang=en

For the debugger, Visual Studio 2008 SP1 contains:

1. As with all service packs, fixes for all the significant bugs that we found since Visual Studio 2008 RTM.
2. Improved support for downloading symbols and PDBs for the .NET Framework and other Microsoft products.
3. Improvements for using Visual Studio with non-local symbol stores (such as the Microsoft public symbol servers)
4. Step into specific for managed. We have had this feature with native for years, with SP1 we added this support for managed as well. If a line contains multiple function calls, you can right click on the line in the editor and select which function you would like to step into.
5. Step filtering for managed. There is now an option to stop stepping into property get routines.

We want to try and get the RTM version into customer’s hands as soon as we can, so this means there isn’t too long for us to act on customer feedback. So if you are interested, give it a whirl soon.

One very important note: If you have installed any Visual Studio 2008 hot fix, make sure that you run this tool _before_ installing Visual Studio 2008 SP1 Beta:
http://code.msdn.microsoft.com/RemoveKB944899

If you would rather not run a tool, manual steps can be found here:
http://blogs.msdn.com/heaths/archive/2008/05/16/kb944899-should-be-removed-before-installing-visual-studio-2008-sp1.aspx