Jason Sutherland is a program manager on the developer division's release team. Translation: his team builds the .NET technology and hands it to the Longhorn team, which then builds that into Longhorn.
He has one of the best seats in the house to see just how Windows is changing (hint: the .NET Framework and CLR are being built into the operating system for the first time).
He talks of the change as a "huge bet" approach. Why is this such a huge bet? Because now that the operating system itself is relying on .NET (WinFS and Avalon, for instance, are being written in C#/.NET) there become really strong dependencies on the .NET
system. Plus, there's a huge amount of pressure on the developer division to make sure that .NET is performant, reliable, and secure.