I was really pleasantly surprised by my visitors after Natalie's birth. Most of our friends stayed away for the first week or so and our family were great - popped in for a visit but never stayed for too long.
I hope it is the same pleasant surprise for you
I guess the good thing about being at home is, like Nic said, you can just take yourself and bubs off for a feed/sleep whenever you feel like it and let DH deal with the fam. I did this a few times when immediate family came round (cos I knew they wouldn't care) and if other family / friends had've stayed beyond their welcome (it didn't happen - yay!) I would've done the same thing even though it kind of feels funny... You'd get over it!
People are pretty good about responding to your openness to IME. Don't hide your feelings. If you're not confident telling people to leave, feel free to yawn loudly, burst into tears, exclaim loudly how tired you are, etc etc. That's one way to get the message across