Here's what's brewing in today's Coffee Talk: Serena Williams says she used to want to look just like her big sister Venus, and tells why she and rapper Common broke up in April. Chris Rock and Adam Sandler are working on a Richard Pryor biopic. Guess who's playing Pryor. Hint: it's not Rock. Plus, Diddy's party gets shut down and the Obamas watch 4th of July fireworks on Capitol Hill.