Does not compute. OS innovation != cross platform. Language innovation can help with cross platform coding if the language implementers are sufficiently clever. See, for example, Perl's fork() implementation on Windows. Not perfect, but better than anything MS is likely to give us in the next 10 years.

I think Erlang is about as close to "OS innovation" as you're likely to see in this space. The Erlang runtime is practically a little OS unto itself with its own process model, networking, storage, etc.

-sam