Well some become DT's and some could eventually move to OL possibly.
I think the big thing is that having having two DE's that are pass rushing threats can help make you a dominating defense. If you can find at least one rush end, a good MLB and one good corner, you're in good shape. Look at how many plays Titus disrupted last year? I'm not sure we have that same kind of player right now...some of the freshman might be but who knows. It's a position you can stockpile b/c of the ability to move them to other spots.