I'm a junior now, and I think my parents are still having a bit of a hard time "letting go". (I'm an only child.) I don't think they'd have any kind of problem with me moving back home after college for a while, in fact they would probably welcome it -- but that doesn't mean I'm going to do it!!!
I stayed home last summer, and it was alright, but also a bit strange. I have a wonderful excuse to go home again this summer, and the next (my parents live in Germany -- how could I pass up Europe???
) But past that? I don't think so.
I couldn't imagine living with my parents when I'm in my late 20's and on...it just work for me. Maybe it fits other people's styles, but not mine!
To echo what others have said, there's nothing wrong with it for some people, as long as you do basic things for yourself like clean your own bathroom, wash your own clothes, help around the house etc. Don't be a lump who sits in your parents' basement and plays video games all day!