Trying out a new room situation

So Caleb is 18 months old and still doesn't sleep through the night.  He can fall asleep by himself, but I have to sit in the room with him.  Yes, I know - this is my own fault and I take full responsibility.  What can I say, he's the spoiled 7th kid!  So for a long time I've been toying with the idea of letting Michael sleep in Caleb's room.  My sister and I were talking and she said I should just put a mattress down on the floor and try it for a few days to see what happens.  Well, when I told here there's already a twin size empty bed in there and there has been the whole time (duck my head here), she wanted to hit me from a thousand miles away!  So after much encouragement from Blake and my sis, I finally decided to give it a try.  Last night was the first night.  Michael is thrilled to share a room with Caleb.  Right now Nathan and Michael share a room and they're at each other's throats constantly.  They get along sometimes, but both boys... well actually all 3, seem to think this is a good plan.  So about 10 minutes after Caleb went to bed last night, Michael had to get up and woke up Caleb.  Grrrr!  I was so tempted to just send him back to his room and call it done.  I have a very hard time with any kind of change like this so giving up fast was an easy option for me.  But I decided to stick with it for a week and see what happens.  Tonight I put Caleb in bed and he fell asleep so I left.  Not 5 minutes later he was up screaming.  This time I didn't go in - I wanted to see what would happen.  Michael talked to him for a minute saying, "Caleb, it's Michael.  It's ok."  I was standing outside the door and heard the conversation and I have to say it was so CUTE!  Those two are so close and just adore each other.  Caleb still insisted he wanted mom and still screamed. But to my complete and utter amazement, he only cried for maybe 5 minutes and that was it!!! Can you believe it?  I can't!  Could this be the start of him sleeping through the night?  (Oh wait, I didn't just say that?  Because that would jinx me to say it out loud, as we learned in my puke post.  So scratch that!)  But I'm so excited to see if this works.  I'll keep you all posted...