Nix has stated on more than one occasion that the Bills will be drafting for the 3-4. After last year's poor production though, there have been a lot of different things that they tried to do. They know they have a guy that they can build around in Kyle Williams, but we all know he is not a prototypical NT for a 3-4. I have a feeling that our draft guys realize this too and are not going to try and make our current players be something they are not. They want to put them in a position to make more plays and not get "ball and chain" married to a scheme. The hybrid talk by Gailey indicates that they want to build off our current strengths by putting our play makers in a position to succeed. That being said, they will draft the guy they think will have the greatest impact regardless of whether they are projected as a 3-4 or 4-3 player. I really think that they want someone next to Kyle "The Wrecking Ball" Williams to put some real pressure on offensive lines. To me this sounds like it would be a 3-4DE/4-3DT. Someone that can do both. This way it will be a top draft pick that will play next to our current probowler and have a chance to really dominate.
As for Von Miller, I really like him. I just don't know if the Bill's will be willing to take him at #3 and try to find someone to go next to Kyle later. They said they want at least 2 more DEs and it seems to me that they will want one in round one.