This is interesting:

• Premier VSIP (Visual Studio Industry Partner) customers will have access to Visual Studio source code

Why do I think that's interesting? I was a little bit less surprised when they announced earlier that the .NET Framework source code would be available for people to look at - after all, we could kind of do that before with reflector.

This is different. I bet there is much more legacy code in VS than in .NET. You can kind of tell from the API...all the COM stuff that's there and the way there isn't much in the way of taking advantage of .NET features like reflection in the VS API. To me, and I'm just imagining here what it must be like for partners like TestDriven.NET, DevExpress, Resharper, and Softperson, this source code - the Visual Studio source code - is much more important and valuable. There _was_ no reflector for this stuff, and it seems, in my limited experience building add-ins with Devexpress's DXCore, that there are a lot more great mysteries here than in the rest of the .NET landscape. It seems like Visual Studio is the Marianas Trench of the .NET world.

I can't wait to see what awesome new things the Visual Studio Integration vendors will come out with next.

The only one little nit picky thing that I see that I kind of don't like 100% is that it looks like this behind the curtains access is only for premier VSIP members. I wonder if they would wave the $10k/year * 3 years fee for open source projects that want to integrate with visual studio. Or are those guys just out of luck?