I just saw this article over at the Winformat web site. Exclusive: PDC Attendees to Get Aero Demo Only

Which states that according to "sources" that have spoken to Paul that Aero will be not included in the DVDs given out at the PDC. The main reason being to ensure that competitors are not able to copy Aero before it is launched. It is a curious statement to make when you consider the market shares of Apple and Linux in the desktop markets where Longhorn is targeted.

I would have thought what might be much more dangerous is someone providing a piece of freeware that runs on top of Windows XP and 2000 that provides say 80% of the look and feel of Aero as that would make Longhorn look old before it is launched and potential surpress sales of the os. Are Microsoft really scared that they could lose market share by it's competitors getting an Aero competitor to market earlier than them ?.

I would have thought a more plausible story must be that they have not reached the point in the code cycle where it is ready for more general distribution. I wonder what the true story is.

[WebLogs @ ASP.NET]

I hope Thurrott is wrong on this one, but the Longhorn backchannel has been consistent with Thurrott's story so far.  This has been hinted at over the past few months, and now it may be the reality.  We'll see.