They're not going to do the Mandarin because they said he would take too much to develop. The closest we got was the terrorist group 'The Ten Rings' that kidnapped Stark in the first place.
As for Whiplash, I was kind of disappointed when I saw him, since his suit didn't have any real protective covering, or so it seemed. He didn't even have a mask, I imagine a sniper could have picked him off easily and I can't imagine Iron Man not having an armed escort when not in armor. Whiplash probably has some electromagnetic thing to catch bullets, I'm guessing, he wouldn't leave himself vulnerable like that.
But toward the end of the trailer where Iron Man and War Machine were blasting away a bunch of what looked like android copies of them, that looked like a major plot twist nobody would have expected to see! I just wonder what Sam Rockwell's role as Justin Hammer, a rival businessman of Stark's, is going to be up to.