Maybe I'm an outlier, but the self-taught people I know fare particularly well on compilers and machine-learning among my peers. Maybe it's the circles I travel in, though. :)
FWIW, I'm a self-taught information-retrieval / compiler / linguistics geek, currently studying machine learning. I've been programming since I was 5, and I always wanted to be a super-librarian, whatever that meant.
The majority of people I've come across started by doing web stuff or Basic way back in the day. I think in general that's the largest population. The best self-taught people I know have by now read everything that would be in a university reading list anyway.
I think it reinforces the point that self-taught people become very knowledgeable about the things they're interested in. The average self-taught programmer is likely to be more motivated than the average new CS grad. Although this may be becoming less true as more of the less purely interested people move to the more "practical" software related degrees that exist.
FWIW, I'm a self-taught information-retrieval / compiler / linguistics geek, currently studying machine learning. I've been programming since I was 5, and I always wanted to be a super-librarian, whatever that meant.