The one time small school riser (maybe the trend setting for fans and teams trying to find that next great non-FBS talent) has 13 interception in his 3 year career thus far (with Arizona), and that big play ability could prove more valuable than the 2nd round pick the Eagles received in return.
The old saying is that the best defense is a good offense, and the Colts, Patriots, and Saints have used that to their success in past years. While the Eagles defense as a whole isn't bad with or without DRC, having Michael Vick, DeSean Jackson, Jeremy Maclin, and LeSean McCoy on offense means that in any one game, it's not out of the question to expect 30 points per game.
The Eagles offense was 3rd in points, 2nd in total yards, and in the Top 10 in both passing and rushing, and they added even more talent to their running game in the draft. Having a stable , high scoring offense puts the opposing team into much more obvious passing situations. And with the length and recovery speed of DRC, it'll be less about sticking his man and more about getting to the spot when a quarterback makes a mistake.
Having talent on your team never hurts for a player stepping into high expectations, and with two other highly qualified and highly talented defensive backs in his unit, the adjustment should be quite smooth for DRC to be the 2nd or even 3rd best player in his own secondary.
Nate Allen had 3 interceptions and 48 tackles last year and was on track to be a strong contender for the Defensive Rookie of the Year before getting injured and missing the last part of the season. Asante Samuel has had at least 6 interceptions in each of his 3 seasons since coming over from New England, where he had 10 interceptions in his final year there.
The Eagles second most productive defensive back when it came to interceptions was Dimitri Patterson. A former undrafted free agent signing of the Redskins back in 2005, Patterson started 9 games for the Eagles last year and had 4 interceptions.
While he did play well, there are a few things to keep in mind. One, he's not as athletic, dynamic, quick, or explosive as DRC. Two, he had all four of his interceptions against three sub par QBs last year: Alex Smith, Donovan McNabb, and John Kitna. And three, all of those quarterbacks had multiple interception games that week.
So if Patterson can have 4 interceptions, a cornerback longer, quicker, more experienced, and more proven steps in, he should be able to maintain that productiveness at the very least in the Eagles system.
Having a fierce pass rush makes coverage and pass breakups (potentially interceptions) much easier for secondary because quarterbacks (especially young ones) tend to be over-willing to force passes, float deep balls, or just miss cover guys altogether.
Trent Cole returns to the defensive line, where he had 10 sacks in 2010. Brandon Graham, Optimum Scouting's number one rated defensive end in 2010 NFL Draft, was hurt all last year, and he should be ready in the next few weeks. Juqua Parker returns as well, as he had 6 sacks last year as well. Add tons of defensive tackle depth to this team, and it's easy to see how the defensive line should be a huge asset for the secondary to benefit from.
While the Philadelphia media will blow him up and then break him down a lot before he plays his first game with the Eagles, Philly fans should know one thing: DRC is VERY talented. He went in the Top 20 on draft day almost solely because he was a workout warrior and has the length (6'2) and hip fluidity to cover any receiver in the league.
Over his career, he's averaged around 46 tackles, over 20 passes defended, and over 4 interceptions per season, and that's with a very average pass rush. So add DRC to an already talented secondary, and you could see why getting a feature cornerback and a 2nd rounder may end up being the steal of the year in the NFL.