Borderlands 2 - Video Interviews @ G4, BuzzFocus

Both G4 and BuzzFocus have video interviews for this game. They both talked to Jasper Foreman about enemy behaviour and the improved AI. In the interview with BuzzFocus, Jasper mentions a new type of enemy the Goliath that likes mutated midgets apparently:

For instance, two enemies have a slight romance that can cause big trouble for players. The mutated midgets we saw in the first game, will now interact with one of Jasper’s favorite new enemies, the Goliath. Foreman told us: “If a Goliath and a midget get in close contact with each other – they kind of like each other – the midget will hop on his back and be an even more powerful enemy.” Regarding gameplay, Foreman warns us that we should expect tougher challenges. A battle with a Goliath can quickly turn into a mini-boss battle depending on how you attack it. “He Hulks out,” Foreman says.