The Cliff Avril saga is continuing to roll along for the Lions, and unfortunately for Detroit it looks like Cliff is not going to stick around unless they start mailing him a much larger paycheck. No hometown discounts, and all that. Cliff will probably be irreplaceable for the Lions if he leaves -- how many 11 sack per year players are there out there for the price that Avril was being paid? -- but the draft might be the place the Lions will look for his replacement if he ends up leaving.
The new SB Nation 2012 NFL Mock Draft is now out, and they have the Lions going along in that vein. There's not going to be very many slam dunk players at 23rd overall, but certainly there is room to grow their already beastly defensive line up a bit more with young talent. The SB Nation draft says that South Carolina DE/OLB Melvin Ingram will be the guy.
Ingram is the best player left on the board, and the Lions could use some insurance in case Cliff Avril is too expensive to re-sign. Ingram specializes in rushing the passer, which will be important when facing Aaron Rodgers twice every season, but he can play against the run as well. This would be a steal for the Lions at this point. You can never have enough pass rushers.
The key to the Lions success on defense in 2011 was their defensive line being absolutely beastly. They're not particularly weak at the other positions, but that's their core and it can't hurt to build up your core a little bit more. Of course, this will remain dependent on Avril's ability to negotiate with Detroit for a new contract; he already stated that he will not be happy if the franchise tag is slapped onto him to keep him around.