He's got the size to play outside in the Packers 3-4 scheme (6-3, 254 lbs.) and I was really impressed with his agility during his workout at the NFL combine. He's a proven performer on the field too, after concluding an impressive career at UCLA.
But, as Wes Bunting writes about, he had a lousy 40 time at the combine, and he's looking to improve on it at his upcoming pro day. In the case of Ayers, I don't think much of his 40 time, and expect he'll be worth it at the end of the first round.
But I'm not sure if he's worth it for the Packers. They don't have a clear favorite at starting outside linebacker opposite LB Clay Matthews, but they have some options. Plus, they've spent an awful lot of money on linebackers in recent years (extensions for Hawk, Bishop, Chillar) and they already have one high paid decision to make about LB Nick Barnett. As much as I like Ayers, there are a lot of good players available at the end of the first round, and I think the Packers should look at other positions.