We first brought our twins to WDW when they were nine months old and their big sister was 3. We had a great time. And by we, I mean everyone: me, hubby, and all three kids. But I will tell you that the thing that made this work is that we brought our trusted and trusty babysitter with us. We had a two bedroom villa and she was gracious enough to bunk in one of the bedrooms with our oldest, while we had the twins in cribs in the room with us. Your helper doesn't have to be a sitter; it could be the grandparents or your sister or a friend -- anyone who can help you carry gear, change diapers, take the fussy one out of the restaurant, or sit with the napper while the others visit an attraction.
I, like all the moms on the panel, truly (really truly) believe a child is never too young to bring to Disney World. Kara writes about this
HERE, I write about it
HERE, and Kim writes about it
HERE. I cherish the memories of those early trips with the girls. But I also remember the struggles of having to deal with three kids under the age of four: the endless diaper changing, the sleepless nights, and the incredible amount of stuff needed to take care of that army. Obviously I am a HUGE Disney fan, and I encourage people to visit when their kids are small, but I could not in good conscience tell you to go with three kids that small without some help. In my opinion, it would be overwhelming. Bring a sitter or grandma and you'll have a great time, but if it is just you and hubby, I'd wait until the twins were about three or four.