One of the comments Miguel makes is, "The only part I really focus on is the .NET development environment. I don't know about all the rest."
What those of us who actually use Internet services are concerned about is "all the rest". Let's not forget that MS's goal for .NET is to tie all the open pieces together with the proprietary stuff like Hailstorm... and Hailstorm scares me silly.
If developers adopt, say, C#, then that language will gain wide acceptance. Doesn't sound like a large problem on the surface. After all, I could write open source programs in C# as well as in C, right? The problem is, nobody will do C# better and provide more compelling tools than MS. When MS controls one standard -- C# --they gain leverage in the market to push developers toward the rest of the .NET package, including Hailstorm.
I hope Miguel and O'Reilly will take the time to think about the part about "all the rest" and not give MS more rope to tie us up with.