The Pack at #5
If they stick at #5, I'd look for AJ Hawk or Mario Williams to be the pick. Their 2 biggest areas of need are LB and DL. Hawk is an animal and would instantly improve their rush D. Williams is an all around DE that could dominate games. He has the size, strength, and speed to be an everydown star.
If they trade down? Maybe they'll take a look at Chad Greenway or Rodrique Wright. Gotta load up on defensive talent if they want to make major strides next year.
But what about the offense? For the sake of discussion, let's assume Favre retires and Rodgers gets the job at QB. The RB situation is a mess and they need to decide what to do with Ahman Green and Najeh Davenport. Green is definitely on the downside of his career after a spectacular run with Green Bay. He'll probably command too much $$$ for the Packers to keep him around. Davenport is skilled, but very injury prone. Could be a bargain for a 1000 yard rushing talent, though.
The WR position is pretty well set with Javon Walker, Donald Driver, Terrance Murphy (when he returns from injury), Antonio Chatman, etc. The OL needs some help in the middle but the Tackles are very solid.
Here's my mock Packers draft by position assuming they trade down in the first round to pick up an extra 2nd round pick:
1st - LB
2nd - DL
2nd - interior OL
3rd - DB
4th - LB
5th - TE
6th - LB
7th - DL