There was an interesting post on co-sleeping on Daddy Dialectic recently. Jeremy Adam Smith discusses his personal experience as well as some other opinions both for and against sleeping with your baby.
The fear with co-sleeping is that you will roll over and squish your child, either because you are sleepy or because you are inebriated. I can see that it could be dangerous if you're such a heavy sleeper that nothing wakes you up, or if you're chemically impaired.
On the other hand, parents have been co-sleeping with their children for millions of years. In many other cultures today, co-sleeping is completely normal and expected. Indigenous South American peoples, for example, would view our culture's practice of putting a helpless baby in another room, far from its parents, as barbarous.
There are valid points on both sides of the debate, which probably means that the best position is somewhere in the middle. Ultimately, it is up to the parents and the child to determine what is best for their family.
Vinny slept between us in our bed for the first several months of his life. I loved it and so did he. It was definitely the right thing for us.
I tried putting him in a bassinet next to the bed, but that really didn't work for us. I had a hard time lifting him into and out of it (because of my arm), and he didn't like being alone. I soon realized that he would sleep four hours instead of three if I kept my arm around him as he lay sleeping. That alone was enough incentive for me to let him sleep with us.
It was more convenient to have him right there when he was still small and needed nighttime feedings. While I didn't breastfeed him, Jeff and I could both sense that he was going to wake up hungry soon, and get his bottle prepared before he got upset.
Another thing I really liked was the fact that I could use my body to soothe him, even if it wasn't through breastfeeding. The sound of my beating heart and steady breathing were comforting to him and that helped me feel not quite so bad about my inability to supply him with soothing, natural breastmilk.
At about six or seven months, we started transferring him to his crib after he'd fallen asleep. Vinny would go to bed with me and fall asleep. Then, a couple of hours later, when Jeff was ready to go to bed he'd move Vinny to his crib and then go to bed. This combined the best aspects of co-sleeping and separate sleeping.
We finally stopped co-sleeping altogether when Vinny started rolling. I was afraid that he would roll off the bed in those hours before Jeff got there. I guess he was accustomed enough to the crib at that point that he wasn't afraid to be in it awake and alone. I would follow our bedtime routine and rock him until he was drowsy enough to fall asleep before putting him to bed.
We co-sleep very rarely nowadays. Last weekend he woke up before dawn with a bad dream or something, so I brought him to our bed. But he rolled and kicked enough that Jeff left and slept in the guest bedroom. I got little sleep that morning, so overall, I'd say that nowadays co-sleeping is a bust.