I did the cot trick that Fiona was talking about... I wanted to gradually get him used to his cot again, but didnt want to force him to have sleep away from us, so we moved the cot in our bedroom, took one of the sides off and had it has an extension of our bed (he was 9 months at the time)... it was another 4 or so months after doing that when we moved Aidyn back into his room.
After he moved back into his room there were still periods when he would spend the night in our bed, and that was fine with us. Now that he is over 2, it happens less and less.