When I bought Borderlands, I was excited. I was expecting a game who combined the action of a FPS with the deep stories, characters and customization of a WRPG. What I got was basically a game with the worst of both worlds. The action was interrupted by the long stretches you had to walk and/or drive, an story almost non-existent and characters that the closest thing of a personality was the cool introductions.
It is not that the game was bad. it had cool stuff like the class system, the guns, the art direction. But I was expecting more from it. I trade it after a few hours of play (and, in fact, I regret it, but I regret trading all games I traded), but I was a bit frustrated because it had so much potential and it was wasted. But Borderlands 2 have a chance to right all wrongs Borderlands had.
After playing Kingdoms of Amalur: Reckoning, I wish the same quest structure in Borderlands 2. You finish an event in the main quest and you are already pointed to what to do next in the main quest. So, if you want to do the main story first, you just need to keep going. Borderlands felt that after each quest I needed to go back to the main base to find out what to do next.
I also do no want characters who just looks cool, but that are actually cool, with back stories and dialogues and this kinda of thing. Even COD have dialogues that are worth listening, why not Borderlands 2? I haven't finished the original, but the scenarios were too samey. Hope they fix that in this sequel, or at least make the scenarios changing faster.
I also want a game that doesn't feel you need three other players to enjoy. Borderlands felt unfairly difficulty at most of my time playing, like they were saying 'no, you cannot have fun alone. Sure we made a single player campaign, but you will play co-op. No, we don't care you have nobody to play with, loser'. I want to have fun all the time I play, not just when I have someone to play with.
Lastly, I want a game where I would love to spent time exploring the world, not getting bored walking around. Do this, and this is a game I might buy.