How about adding, to the American pavilion, some attraction about American sports. They could have rotations, year-round, of various sports' stars giving talks and autographs--baseball, football, basketball, soccer, tennis, golf, etc. in a sports setting like a mini football field with astroturf or a mini-baseball diamond, etc. Kids could try throwing, kicking, batting, serving, putting, etc.
That would distribute the crowds from TT and Soarin' once World Showcase opens. I know there is the Wide World of Sports, but, really, not many people go there, do they?