Besides good walking shoes, what type of shoes do you like for the theme parks? Can you wear open toed shoes? Can you wear sandals that strap on? Flip flops? Will your shoes get wet on the water rides?
I like Teva Mush flip flops (and I'm not a flip flop person). They're comfortable, lightweight. Your feet will get wet on water rides, which is why I prefer sandals to sneakers at WDW.
Another fan of flip flops here (Tevas). Although this year I bought a pair of crocs I'm going to try, and always bring a back up pair of sneakers. (I have arthritis in my ankle and sometimes swell up - its easier to wrap and wear sneakers rather than flip flops.)