As far as giving up a lot of yards, our secondary was really poor last year. But, they were really good at getting take-aways (moser stripping the ball) and they did not give up a lot of touchdowns. It was a bend but don't break defense that capatalized on opportunities. That has to do with defensive play calling so I can see similar things from the secondary this year. Keep recievers in front of you and then go up and make the play.
As far as depth. I think our depth is really good compared to last year. If one starter from the d-line or secondary would have gotten hurt last year, we would have been in trouble. Right now, it looks like we might be playing at least 7 d-linemen per game compared to 5 last year. As a group, our linebackers are probably more "talented" but need more starting game experience. I can also see us playing up to 6 different lbs if you count Kris Means.
Also, James Smith at SS is going to be exciting to watch. If he can keep mental errors to a minnimum, he could be great. The secondary will also have better "depth" as far as people that can be counted on to play in nickel and dime packages. However, our lbs are so athletic, I can see us keeping all three in the whole time like Iowa did last year with Hodge and Greenway.