...of course, he doesn't remember it! but he's been back twice since and going for #3 here in less than 3 weeks.
going with a 2yo is what you make of it. you didn't say if you were doing the 3-, 4- or 7-night, but so long as y'all still try to stick with his schedule (as much as is possible) but doing naps and getting him to bed close to his usual bedtime, then you should be okay.
when you get each day's navigator, try to select some things he would like to do...for instance, seeing characters, watching some of the tournaments on board, or some of the shows/activities during the day. our son enjoyed hanging out by the pool a lot and having ice cream. if you are on one of the shorter cruises, there will be a lot going on with shore excursions and what not. for the 7-day, you have more time on board the ship.
do plan to take him to flounders nursery at least once during the cruise (so he can play with other kids) so that y'all can do Palos. just make sure you sign him up right away on embarkation day so you have a shot at getting him in one night. flounders charges (it think) $5/hour and the cms in there are just wonderful!
other tips: you can borrow one of their strollers, eliminating the need to bring your own. i don't know if they charge for them now, but they didn't the last time we borrowed one. you can ask for a diaper genie (wish i'd known that on our first cruise with him!). also, if you don't want him to sleep in a pack-in-play, you can ask for a bed rail and sleep him in a regular bed.
bottom line? he'll have a ball! and so will y'all!