...USC safety Taylor Mays.

Here's Kiper's blurb about the Packers' draft needs (link goes to ESPN Insider):

Green Bay Packers
Top needs: OT, S, RB, LB, CB
First round (23): S Taylor Mays
Second-round options (56): OT/G Vladimir Ducasse, , OT Selvish Capers, RB Ryan Mathews, RB Joe McKnight,
Third-round options (86): RB Montario Hardesty, LB Patrick Angerer, OT Kyle Calloway, CB Trevard Lindley
Summary: Need meets value in Round 1 when the Packers solve a problem in the secondary by getting the maligned but undeniably talented Taylor Mays, who showed some caution this year both in coverage and as a tackler, but didn't get a lot of help from a very young USC defense. The Packers need to continue to build the offensive line because Aaron Rodgers was under too much pressure this year, but I also think they want to add depth and talent to the RB position. And you never have too many talented LBs in the 3-4 Dom Capers has installed.

I agree that safety is a position of need (and the last USC defender Green Bay drafted turned into a monster!), but the Packers clearly need to shore up their offensive line before they do anything else.  If Aaron Rodgers isn't adequately protected next season, there's no chance that this offense clicks at all, let alone allows him to pass for another 4,000 yards.  Football games are won and lost in the trenches, and as such teams should generally try to build from the inside out.