I moved back home right before I got married. I taught for a while.
It was a piece of cake and MY Mom was so much "kinder" than I would/will be. She did the cooking and laundry and I DIDN'T EVEN NOTICE!!!

Where was MY head...self absorbed, that's where.
Once you kids move out, our life is set free! I realized that this year because my son is very independent and my daughter works in GA.
Should they, and statistics indicate at least ONE of them will return, we will be more than happy to give them a hand, help them save money and all that jazz. However, I don't want to become the maid again and the kitchen will close when I'm done for the day. I guess the comfort for EVERYONE will depend on their attitude and level of maturity. If they act like a guest, I'll get a little ticked off. If they pitch in, in leu of paying rent, then great.
It could be a nightmare or it could be really great. Just remember, those years you were on your own, your parents didn't try to move in with YOU. Be appreciative and all will be well.