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.