1. Rookies will not contribute worth a flying damn this year.
The Packers drafted Randall Cobb, their second-round wide receiver of the future, to use him in all sorts of crazy ways like Percy Harvin 2.0. The expectation among fans immediately after he was drafted was that he could line up in the backfield, in the slot, outside, run reverses, return kicks and generally make the Green Bay offense that much more awesome.
There's a school of thought that running backs will be a little less affected than other positions, running back being the position where rookie runners tend to have more success (Adrian Peterson or Steve Slaton or Chris Johnson, anyone?) but don't hold out hope for Alex Green to contribute in his rookie year, either. The plan was for him to be the third-down back, but the intricacies of blitz pickups and screen passes are probably best left to Brandon Jackson for another year. You don't want Jared Allen to take Rodgers' head off because the rookie RB missed a chip.
2. Veteran free agents won't fix your team this year.
NFL.com keeps posting articles guaranteed to tantalize fans of struggling teams, hypothesizing where big-name free agents will land and what holes on which teams need to be filled by which player. That's fine, but I wouldn't expect Sidney Rice or Nnamdi Asomugha to come in and be a world-beater on the Bears or Texans. The lack of time to learn the playbook and practice with new teammates also hurts these players, and the longer the lockout lasts, the more pronounced this effect will be. Scheme is so important in the NFL that veteran free agents will likely have little impact, early in the season.
3. But on the whole, veteran players who stay with their teams will be better than usual.
Players in their early to mid-thirties who would normally be going through minicamps and "optional" team workouts all spring and early summer now will have missed all of that. They'll be working out on their own, of course, but one would expect that veterans' bodies will be less tired come the summer. I would expect older players to benefit from the time off, and have a better season in 2011 than they might otherwise have had.