My son was a terrible sleeper, and now at 2.5 he is a brilliant sleeper. He's still in his cot, and more than happy so that's where he's going to stay till he tells me otherwise. There seems to be lots of pressure to do things with children by a certain stage: wean, sleep through, move to beds, potty train, etc etc. I say go with what suits your wee one and ignore what everyone else is doing!