First of all, don't get down on the numbers. The offense no longer uses a pure fullback. Right now, with Clear off the depth chart, there are four scholarship TEs on the roster. That's just about right for the number of guys you want on a roster. That means all four get to play in a game, and nobody's parked on the bench.
Aside--TEs do a lot. Not only on offense, but on special teams.
In a perfect world, you'd have 5 on your team: redshirt Senior, RS Junior, RS Sophomore, RS Freshman, and a redshirting Freshman. Perfect scenario, and whatnot. Here's the probable depth chart for NC State:
RS SR Rivera
RS SR Bartholomew
SO Downs
FR Meredith
The only downside I see (roster-wise, not player-wise) is that you bust Meredith's redshirt. As far as 2012 goes, they'll have numbers. Downs passed Clear last year, and if he was 50 lbs heavier, he'd be fighting for the starting spot. He's a good option as a complimentary TE right now.
Can't replace the linebacker smothering with any of them, though. Could do like Alabama did a lot last year and use a tackle-eligible. Not sure Clear was ever going to be a receiving threat here, honestly.
As far as future prospects, the roster loses two seniors next year. I noticed they weren't really doing much with TE recruiting this year (can you blame them?). That should pick up precipitously. There's several things they can do with the current roster for 2013. There's always the dreaded position switch for somebody with TE-ish size.
But I'm still pretty sure they're only going to take one TE in the class, even with needing to replace three players. The prospect of being playing early at TE for a big-name school is gonna be tough for the best prospects to pass up. And the great likelihood of not being redshirted will help Tennessee's cause.
For the probables, I'd say GA Arshad Jackson, NC Lucas Wilson, TN Mack Weaver, and NC Josh McNeil are all likely candidates. Look for Tennessee to sign one of them (or two, the coaching staff has been notorious for not obeying me in the past).