I too have a boy when I always expected to have girls (I'm one of three!). I'm due to have a surprise baby in a couple of weeks, and like you, although the idea of having a girl is very nice, I will be delighted to have another boy for my son... It would be so great for him to have a loyal buddy for the rest of their lives!
My husband doesn't get on great with his mum as she was very young when she had him and pretty much shipped him off to his (wonderful) grandparents' for much of his childhood. I feel my husband is pretty unfair with her though as his father was as much a part of that decision as she was, and his grandparents were wonderful with him, but he still considers that she abandoned him. His brother, my BIL, was born later and my MIL was more prepared for motherhood, so they have a good relationship.
My sister's BF is one of two boys who are EXTREMELY close to their parents... not in a weird kind of a way, but like how me and my sisters are with our parents. Regular phonecalls, coffee-stops, Sunday lunches, Christmas get-togethers... They are affectionate and jokey between each other, and it is so lovely to witness.
I think it all boils down to how you are as a parent, and to the characters of everyone involved. Afterall, having a girl doesn't guarantee a close, loving relationship...
Goodluck with your boys... I'm sure it will be wonderful!