Only Kingpin?
That's actually something I give the '03 Daredevil credit for, is it's ability to hangle three of the character's major antagonists in one film rather effectively. We didn't really get to know much about Kingpin or Bullseye, but we definitely knew who they were and their place in things.
I'd want to see Daredevil's proper origin with Stick, the ninjas, the whole deal. Kingpin's such a big deal, I'd even say give him the TDK/Joker treatment and hang onto him for when things get really serious. Mention him, keep him in the world, but I don't think a hero should immediately face off with their arch-nemesis.
And beyond that, what should the movie really be about? That's the real question I rarely see asked here. It's always 'It should be this villain!', but if we keep aiming for the simple 'this hero vs. this villain' formula, we're just going to keep getting the same stuff shoved at us.
I want a story about Matt Murdock and the things that make him who he is.