My biggest point about the 2011 Packer defense is that they were not a championship defense. OK, fine, whatever, we can argue they weren't the worst in the league, weren't horrible, etc. etc. etc. None of that ultimately means much to me, though. I want/expect a championship defense (which doesn't have to be truly elite for this team, thanks to the offense. Just much better). It was painfully obvious that if the offense had a bad day, the defense wasn't likely to bail them out (although I don't think any of us expeted the type of performance the offense gave in the playoffs).
So ultimately, a mediocre defense doesn't comfort me much more than being a horrible defense (although I do tend to lean towards Tramon Williams perception of a "horrible" defense). Anything else is just something to debate and discuss while sitting at home and watching the playoffs instead of rooting for the Packer's in the Super Bowl.
I've said repeatedly I expect them to be much improved in 2012. Unfortunately, that doesn't mean anything for the 2011 season, either.