Oh, I have no doubt that Oxford or Cambridge are great places to go to and have a great many working class, middle class and upper class students from all sorts of schools.
However, I think that we do see university as the be all and end all, especially institutions such as Oxbridge and we should be able to say if we don't think they are right for us without people assuming that we weren't good enough to go. Or to decide that it's not for us (which would solve a great deal of problems right now. IMHO there are too many university places and there are people going who shouldn't be).
I turned down Warwick, UCL and Manchester. Not a comment on my political views or anything, they just didn't feel right when I was at the interview. (As it turned out, I found University to be a complete waste of time and I wish that I had had the balls to save upto pay to go to Drama School the first time around instead of going to uni "because I got a grant and my teachers said that I should").
Everyone's different.
What is interesting is the statistics on black students at Oxbridge. However, I think it is a little unfair to publish these without comparing them to figures from other UK universities.