If I had to pick an odds-on favorite for "happiest Buffalo Bills player" today, I'd go with quarterback Ryan Fitzpatrick. Despite the obvious (that the team doesn't see him as a long-term starter, and that they'd really like to get a franchise quarterback to groom), Fitzpatrick exited draft weekend as the unquestioned starter in the final year of his contract. If he performs well, he'll likely get a lucrative contract - whether it's an extension in Buffalo, or a deal in another city.
While things are peachy keen for Fitzpatrick at the moment, the situation is far more dire for the Bills at quarterback.
The only other quarterback under contract is Levi Brown, a seventh-round pick a year ago who has some natural talent, but looked lost in the pre-season, and then again in a brief appearance in the team's regular season finale. It's possible that the team could bring back Brian Brohm to back up Fitzpatrick for one more year, but Brohm looked worse than Brown, and he didn't even get a restricted free agent tag prior to the lockout.
Buffalo won't be able to address this issue until the lockout ends, one way or another. Expect them to add two players - one a non-threatening backup to Fitzpatrick (Matt Moore, Drew Stanton or Billy Volek could work), and perhaps an undrafted rookie (such as Pat Devlin, Scott Tolzien or Adam Weber). That might look equally bleak to some, but at minimum, the Bills need to double up their body count here ASAP.