I never returned home after university but five years later ended up with my mother coming to live with me (if you are thinking of this DON'T do it). I don't think I was expected to return home especially since Mum had sold up and moved into a granny flat in my brothers house - might have been nice to have the option! Geoff stayed on in Cardiff for a while after he finished at uni but ended up back at his parents house when he got a job in Bradford until I rescued them from him fifteen years later.
My own children are coming to that age now the eldest (19) works but doesn't earn enough to move out yet Alec (17) will probably go to University in 2005 and I can imagine he will want to set up on his own somewhere after but it all depends on finances. With huge student loans it may be impossible to do other than return home.