(X-POSTING: I posted this to another "Little Kid in Epcot" post recently).
My kids loved Epcot when they were that age.
The Figment ride (Journey into Imagination) and the Imagination Pavilion were their favorites. They loved the jumping water fountain outside that pavilion, too.
Soarin' is a great ride, but they really liked Living with the Land (the boat ride in the Soarin' pavilion). The part where the boat goes through two solid walls of fish tanks was a huge hit.
They loved the Seas with Nemo and Friends and Turtle Talk with Crush.
We had a really great time trying different sodas at Ice Station Cool.
They were cool with Spaceship Earth.
The boat rides in Mexico and Norway are also great for kids.
My kids love the train display between Italy and Germany.
Besides the rides, I highly recommend taking little kids to the street entertainment in Epcot. You can pretty much go from show to show all day and have a great time watching the Voice of Liberty and the taiko drummers and the Japanese story teller and the acrobats.
If you want to see more of the pavilions, the kids' craft stations are good for ten - fifteen minutes while a parent looks around. (We switched off watching the kids and looking around.)
The Kim Possible Adventure is an awesome way to see the pavilions, too. The two year old won't be able to find the clues, but would have a good time with all of the interactive, animatronic stuff that it does. My youngest was 4 the last time we were there and wanted to do Kim Possible ALL DAY.