My family and MIL came to visit me in the hospital after giving birth and I didn't mind at all as it had been planned and they all said if I didn't want visitors then just to let them know.
I have heard of people who don't want people in though and they just get a swarm of visitors descending on them and being quite intrusive. I think visitors are OK on the patient's say so and to be curtious and not outstay their welcome!
Visitors are fine as long as theyre planned visitors, there are nothing worse than unplanned guests - newborn or no newborn.
However, all visitors must bring a balloon!