Longhorn won't be based on the .Net Framework

Developers say there's a dirty little secret about Longhorn that few Softies are discussing publicly: Longhorn won't be based on the .Net Framework.
We're still expecting that the .Net Framework will ship with Longhorn – on the CD and/or "in the box" in some way. But the .Net Framework won't be at Longhorn's core, we hear. Instead, the .Net Framework will be the core for a small subset of Longhorn, specifically the Windows API Platform (WAP), which consists primarily of the "Avalon" Windows presentation system and the "Indigo" Windows communications system, our tipsters say.

(Maybe Microsoft's revelation on Wednesday that the .Net Framework 2.0 beta is breaking applications has something to do with this? We're waiting for official word back from Microsoft.)

We're guessing that Microsoft will maintain that nothing has changed – that no one ever promised the .Net Framework 2.0 would be the foundation for Longhorn. But developer types we've been chatting with seem to find this update a newsworthy revelation.