I do not know enough about the technical issues in .NET.
But I do agree with Jamie that engineers should look at the implications of their work. I do not think MS will be doing anything for the good of open source, not even as Talli says getting people to use it.
MS on the other side gets a big benefit by getting more applications running on their platform. That is the difference between vaporware and a real product.
I would prefer that my efforts go into integrating the web services of openACS with office applications like openoffice.