Lil Mama is definitely hip-hop; so are the Eve and the Diddy. There are purists who'd argue against those tracks being hip-hop on the basis of their being too much fun, but these people would also argue against crunk and snap being hip-hop in favor of people like Talib Kweli. In any event, when Mariah did her duet with ODB in the early '90s, and TLC came along, that changed the game. Also, if you listen to southern hip-hop you'll here that it's not exactly shunning dancehall and Miami bass and techno and house in its sound. But then, hip-hop from the start was into using any sound it could get its hands on.
Re: NOW here's a question