Be prepared for a different type of trip than you might have had done before. This most recent trip was our 4th since 2000, but first with a toddler. We did take him when he was 5 months old but that was almost like taking extra bag that needed a diaper changed. At 5 months he was easy, at 2 years old he was a challenge. We realized going in that we would see and do less than ever before at WDW. At MK he fell asleep in his stroller (ours from home, we drove) even before 10AM. DW and I camped out on 2 rockers in front of Liberty Tree Tavern and people watched for almost 2 hours. It may sound crazy, but it was relaxing. We were finished with MGM so soon he had a nap back at the room and at AK he again fell asleep in the stroller slightly before lunch and we again found a shady spot to people watch. At Epcot he was sleeping in DW's arms as we waited for our table at the Garden Grill but woke up as we tried to seat him on a booth w/o waking him. He didn't cry, but it took a couple of visits from Chip & Dale to get him perked up.
A couple of things that we would've never thought we would spend any time at were the photo cutouts in the rear of the Exposition Hall. He ran around and up and down the stairs and ramps for 30+ minutes. Also in Norway he didn't care much for the boat but for the ramp getting to it. Again he ran up and down, to the boat, off the boat, over and over.
Kids are funny. We thought he would be afraid of the characters and we would we changing his clothes constantly from his possibly playing in the water fountains. He was scared of the water fountains, but loved the characters. I read a tip here that for their 2ish year old they bought the autograph book because then their child had a reason and purpose to see Mickey, etc. That worked for us. We saw him first at PC lobby (during Frances) and as we waited in line (as it turned out our longest line of the trip to see a character) I kept pointing out that the other little kids gave their books to Mickey, he signed it, then Mickey LOVES getting and giving hugs. DS watched all of this going on with each little boy or girl taking it in. When it came to his turn he walked right up, gave him the book, got it back , set it down, gave a big hug, high five and then waved bye-bye as he left. This was his routine for every character. We didn't want to mess him up so he now has Mickey's autograph 7 times in his book with about 4 Chip/Dales, 4 Minnies, 3 Goofys, etc.
Also not sure if you water down your juice for your toddler. But we realized that our DS didn't agree with the water at WDW. He had diarhea (sp?) starting with day 3 until after we got home. Once we got it figured out we bought some more bottled water (DW had brought some for herself that we were now using for him). When he was 5 months old the water didn't affect him through his formula, but now it obviously did.