MSBuild's dirty little secret...
Something that Microsoft's been failing to note in all the hype over MSBuild, is that Whidbey will not have MSBuild support in the C++ IDE. I attended the MSBuild session, and this most certainly was not mentioned (a glaring omission, I believe). It only came up in a casual conversion with an MS Staffer when I mentioned how psyched I was about this tool and how it was going to make my life easier, when he got a chagrined look on his face and admitted that there was no C++ IDE support for MSBuild.
He did note that the C++ IDE would support it in the future, but that future isn't Whidbey.