Pro:Ongoing support from M$
Ongoing for as long as suits them. "Plays4Sure", anyone?
They've come up with quite a few 'revolutionary' pieces of software that they hyped to no believe, only to axe them again in their next major version.
And as far as 'support'from microsoft is concerned -- that by itself is rather overhyped as well. There are countless examples of glaring bugs and ommissions in their software that have taken *years* to get fixed, if ever. There's entire communities dedicated to workarounds for microsofts incompetence.
Unless when you say 'supported' you really mean that you can talk to a monkey that tells you that yes, you are indeed up that infamous creek without a paddle.