I'm not a web dev per se, but I never heard of Rob Conery until now. I now ScottGu, Anders, Cutler, Brumme, Dussud, Crowley, Russinovich, Spiro, even Luca, but never Rob.
Not to say he's not a big name, but to say he's the most high profile MS employee beside ScottGu seems absurd. Even in the dev tools space I think you have to give that to Anders.
Rob is primarily well known by those interested in Asp.net MVC - which, given its roots as a RoR knock-off (I say that with love), tends to mean MS web devs with an interest in OSS will have heard of him. He is also well known from his SubSonic project - an OSS ActiveRecordish ORM.
From your list of Technical Fellows it sounds like you're probably not a web dev, so you wouldn't have run into his stuff. An MS web dev these days would tend to list names like ScottGu, Haack, Hanselman, Conery, Walther, le Roy, Wilson, Verissimo, Lipton.
In other news, Anders is totally the cat's pajamas.
Not to say he's not a big name, but to say he's the most high profile MS employee beside ScottGu seems absurd. Even in the dev tools space I think you have to give that to Anders.