I have some influence over certain hiring decisions at a startup. I'd look at experience like that and think "this guy is probably pretty awesome." The MS name might be a bit tainted, but there's no doubt that they have a lot of very talented engineers, and if you really did pioneer the use of data semantics within Bing, well that's pretty impressive.
That said, we'd look at that experience and guess that you would probably not be interested in working at our startup-sized salaries, so I wouldn't expect much effort to recruit you in the first place. The other thing we'd need to make sure about is that you're not stuck doing things "The Microsoft Way (tm)"; you'd be joining a very different culture and if you're not going to fit in, it's not going to work.
That said, we'd look at that experience and guess that you would probably not be interested in working at our startup-sized salaries, so I wouldn't expect much effort to recruit you in the first place. The other thing we'd need to make sure about is that you're not stuck doing things "The Microsoft Way (tm)"; you'd be joining a very different culture and if you're not going to fit in, it's not going to work.