Via Rob Fahrni, I found this report on Windows Vista development:

Up to 60% of the code in the new consumer version of Microsoft new Vista operating system is set to be rewritten as the Company "scrambles" to fix internal problems a Microsoft insider has confirmed to SHN.

In an effort to meet a dealine of the 2007 CES show in Las Vegas Microsoft has pulled programmers from the highly succesful Xbox team to help resolve many problems associated with entertainment and media centre functionality inside the OS. The team are also working closely with engineers from the Intel Viiv team. and it is now expected that the next version of Viiv could be delayed to line up with the launch of the consumer version of Vista at the 2007 CES Show in Las Vegas.

Like Rob color me extremely skeptical. There is simply no way that they are going to "rewrite" 60% of the code and hit a 2007 release date. I suspect that the reporting was washed through a number of non-technical hands that did not understand what some technical guy said - like a long game of telephone.

Of course, if there's anything even vaguely accurate there, 2007 would be optimistic...