"I suspect that it would give Microsoft a convenient excuse to reverse course on its open-source antipathy and embrace it"

We all know what the 2 other E's are...

in my opinion - if Yahoo accepts; all of the open source projects under its under wing are in danger; I'm already thinking of how to get out of yui...

I hope Pig ( http://news.ycombinator.com/item?id=108224 ) escapes too. It looks very promising.

1) Some of Yahoo's major open source projects are java based that alone is bad

2) Instead of supporting major, mature open source projects with good traction in the .NET world (NANT, NHibernate, NUnit, ...) MS instead chose to reinvent proprietary wheels (LINQ, ...)