Mommy, Change My Diaper

For all of those of you who have had more than one child, I'm wondering how you best prepare that 1st one to not be an only child anymore.  Sure, it has a lot to do with age, I'm sure the younger the easier and maybe the same with the older as well.  I feel like Gage is at a good age to understand most everything, but he is definitely a Momma's boy and I know that he will have some trouble adjusting to sharing me with a baby. 

One idea I had to at least get him used to a baby around is to buy him a baby doll.  Enter 'Mommy, Change My Diaper'.  Now obviously I have zero experience in buying baby dolls, I just knew I wanted some kind of little doy dressed in blue to represent Gage's baby brother.  Most of the dolls I could find were all dressed in pink and dresses, and as much as Gage likes pink I wanted him to have a little boy doll.  I found the 'Mommy, Change My Diaper' doll for a little over $20 and decided to bring it home to him.  I knew he'd like to feed it with its little bottle and help me change his diaper.  It even coos and cries, which is fun, but wasn't a requirement.  Oh, it's also anatomically correct!  Which is a plus in Gage's book.  In any case, the other night when we brought it home, we promptly filled up the water bottle and Gage was excited to feed him.  The directions said that it had a 'delayed water release' so the doll wouldn't pee right away.  However, I'm guessing that didn't mean you should fill the whole bottle up, because only about a quarter way through the bottle, water started pouring out of the baby.  It was pretty hilarious, but now I'm sure Gage thinks that all babies just pee on you as soon as you feed them.  Anyway, I'm open to suggestions if anyone has any better ones of how to prepare him.

Sorry for the iPhone blur, still don't know why people rave about these cameras.

Not really sure what my plan is now, I mean we have this doll we talk to, feed and occasionally change his diaper, but clearly the new baby isn't just going to sit on the couch all day.  Maybe getting closer to my actual DD, we'll start to take the baby places or interrupt play time to feed the baby, etc.  I haven't really thought that far ahead yet.