The Eagles defense had its issues in 2011, but you aren't going to see much personnel change in 2012. Andy Reid will add some more talent through free agency and the 2012 NFL Draft. A couple rookie linebackers who can come in and compete for starting jobs will be good for everyone on the defense. An up-and-coming pass rusher added to the line wouldn't be a bad thing either.
The Eagles defense is in much better shape than most experts will give them credit to be. Better coaching and an offense that doesn't put the defense in tough situations through untimely turnovers will do more then any overpaid free agent or first-round draft pick will this season.
Look for the Eagles to add a couple key veterans to the defense along with several rookies to compete at linebacker. The rest of the defense will look like the defense of last season on paper, but with more chemistry and an emphasis on the fundamentals heading into the season.