On the drive to work today, Chris Sells asked me what was new & cool with Whidbey debugging. Somewhere on my list was "Source Server" support. Chris's ear's perked up at that.
I told him to dig around for an article, as I was sure somebody like John Robbins had already written about it. Turns out, it's not well covered at all (yet).
In a nutshell, source server allows the debugger to download on demand whatever source files you might need. For instance, if I break into a program and it's stopped somewhere in Windows or the CLR, I get the source code, rather than just a disassembly window.
It really is a developer's dream. One of the coolest things I've seen in my 15+ years in this business. Enabling it in Visual Studio 2005 is pretty easy: Tools | Options | Debugging | General, then select the "Enable source server support" button.
What's the catch? For this to work, you need to have a server set up in a specific way to dole out the requests from the debugger. Here at MS, most of our code is indexed on to the source server as part of the build process. Before you ask, I think it's highly unlikely that these will be exposed outside of Microsoft. :-)
However, nothing prevents you from setting up source server for your own code. The documentation and binaries are part of the "Debugging Tools for Windows" goodies. Why there? Because Source Server was originally developed for WinDbg, then subsequently supported by Visual Studio.
While you might not go to this effort if you're in a small development group, I can easily see bigger development organizations jumping on this capability once they know it exists.
Also, before you ask, I'm not the expert on setting up source servers. Never done it myself. I just know where the checkbox is in the IDE, and where the documentation for setting one up is. After all, "It just works!" Why would I need to know anything more? :-)