we're still co-sleeping with our 2 year old, and about to start transitioning him into his own room before the new baby comes. Adam always had his own cot (till 2 months ago when we took it down to move and never put it back up, he'd stopped sleeping in it anyway once he'd figured out how to climb out), and it's a co-sleeper, so he would start off in the cot and then I'd bring him in to bf, and we'd both fall asleep. he always napped fine in the cot during the day, and some nights (not that many, on reflection) he did sleep the whole night in there.
I couldn't have coped with getting up every few hours to feed him, and then later, to settle him. we have a really big bed, so we've always had our own space, and when Adam was in sleeping bags (up to early this summer) he was on top of the duvet. now he's snuggled underneath. I will miss him when he's finally evicted.
I must add, though, I never planned to co-sleep till this age, but until a couple of months ago we were in a 1-bed flat and had no option but to share a room, and when a toddler can get out of his own bed and climb in yours, and there isn't anywhere else for him to go, for the sake of peaceful nights we didn't fight it. with the new baby we'll probably try to make the transition around 9-12 months.