Kevin James hosts the 23rd annual celebration, which honors kids' favorites in film, television, music and sports. Rihanna and Justin Bieber are scheduled to perform. Also: Apolo Anton Ohno attempts a stunt with slime. Among the presenters: Tina Fey; Steve Carell; Chris Rock; Jackie Chan; and Robert Downey Jr. Also: First Lady Michelle Obama accepts the Big Help Award for her work fighting childhood obesity.