Well, mine's still holding on by the skin of it's disc tray... It doesn't shut anymore when you push the disc tray button so I'm sorta just waiting for the ring of death to claim me so I can have the 3-year warrantee apply to me...
Mine has managed to survive, but sometimes it freezes. That usually happens about the same time that it sounds as if there are stones going through a fan. Usually while getting upgrades on Bioshock recently (if I got speedy hacker, it was so distraught that it refused to work any longer).
My 360 ran 19+ hrs a day over the summer (between me and my brother) and it never had one problem until i played two worlds but i am sure that was the games fault.