Some very good posts in this thread so far..
I'll agree with the following:
Anthony Gonzalez - I don't believe Harrison has the desire or youthful knees to continue putting up elite numbers.
Donald Driver - He really wasn't used at all in the red zone last year after Jennings emerged. Did he suddenly become less effective in that area? I don't think so. He was a little banged up and Jennings/Jones both emerged. With Rodgers, we'll have to figure out who the new favored WR will be in different situations. I think Driver is a pro's pro and he'll be a reliable, proven guy that Rodgers will leverage. His ADP and value is as low as it's been in a long while, so he's definitely a good player to gamble on, especially as a WR3 or later.
Vincent Jackson - As others have said, he had a strong playoffs, but he does still drop too many big balls.. With Gates potentially starting slowly, VJ and Chambers will get more work potentially and Buster Davis is someone else that could get some targets there.
Mark Clayton - He was hurt all year and never regained his bounce or separation in/out of his cuts. If healthy again, he should return to his productive self of two years ago.
Others:
Devin Hester - I know the Bears offense looks like a train wreck, particular at QB and WR, but Hester is going to have the opportunity to make the leap from special teams stud to full-time WR like Steve Smith and Derrick Mason did earlier in their careers. With so many QB issues, why not leverage your best player and get him the ball as much as possible on slants, screens, bubble screens and take your shots with him deep, too. Booker is still a physical player and he can be useful, but he lacks explosiveness at this stage of his career and I don't think we should count on him for much more than the usual 40ish receptions per year.
Steve Smith - Even as WR7-9 where he's listed in many rankings/projections, Smith looks like a great value for those who can pluck him in the draft in that area. I guess it depends on whether you are a buyer on Delhomme's elbow or not. The running game should be better. Muhammad and Hackett provide more reliable options beyond Smith than they had last year. The main downside here is if Delhomme gets hurt again. If he doesn't, Smith should easily live up to his ADP and then some, unless he is the one who gets hurt. Very little downside with Smith at his current spot (ADP).
Josh Cribbs - I can't shake the feeling that Cribbs will be one of those waiver gems early-mid season. Stallworth may be a better fantasy name, but I just think that Cribbs is the one who could be a better football player. It's not looking good for Jurevicius. Despite the recent nice things the staff is saying about Travis Wilson, I'm not buying him at all. Cribbs has been the better player there the last couple of seasons and he is going to get a chance to play a bigger role in the offense. JJ hurt, Stallworth is inconsistent, but beyond Braylon and Winslow - Cribbs has a shot to be the #3/#4 target in this offense and I think he has just as much big play ability as Stallworth and he probably will go undrafted.
Mike Walker - He could be cut in training camp or, if he stays healthy, he could emerge as a playmake in the Jags offense to compliment Jerry Porter and Reggie Williams. Problem is targets. I don't think any of the Jags WRs will emerge with enough targets to be more than a WR3. I don't think Williams will catch another 10+ TDs, so someone like Walker, Porter and TE Marcedes Lewis could surprise a bit with an increase in scoring. Walker is a player to watch in camp and preseason. If he starts flashing his potential like last year, get him on your roster.
Will Franklin - Ooof. Devard Darling and Jeff Webb? Meh. Franklin is only a rookie, but opportunity here is the key. Franklin might be enough of a playmaker and athlete to beat out those two and earn a starting job immediately or soon into the season. He's another guy that could be a waiver gem, or a last round flyer. The Chiefs QB looks dreadful right now, but Bowe did alright last year and with Bowe/Gonzo/LJ being the focus of defenses there is room here for someone like Franklin to be a surprise.
Chad Jackson - Will he finally emerge? Great situation if he can make the most of it. Jabar Gaffney had plenty of value down the stretch last season, so Jackson could be worthwhile, especially if Moss/Welker get hurt.
Antonio Bryant - I've never liked the guy much, but he does have plenty of talent. It's too soon to know if Galloway will lose anything. He sure has resisted the natural aging process for speed players thus far, but he can't evade it forever. The Bucs under Jon Gruden are almost a lock to produce in the passing game. If Bryant stays clear of trouble he could emerge as the WR2 here over Hilliard, Stovall, Clayton, etc. That's not much of a stretch. If he doesn't screw up his opportunity, we're talking extremely low ADP and a pass-friendly offense looking for a viable WR2. Hilliard was useful last year in that spot and arguably Bryant has more game. We'll see. I'm still skeptical, but the situation screams value.
Tennessee WR - Like the Jags, the Titans want to run the ball a LOT. VY isn't a WR-friendly QB yet and Alge Crumpler's addition to the team doesn't send warm fuzzies to me with regards to the # of targets or fantasy production that is likely to come from this position. That said, I'm keeping my eye on a couple of deep sleepers here - Biren Ealy and Paul Williams. Rookie Lavelle Hawkins bears watching, too. First, they have to beat players who have produced in spots like Roydell Williams and Brandon Jones, but both of those guys aren't healthy. McCareins, to me, seems like he's holding a spot to keep it warm for one of these other guys to emerge. I don't see him regaining the Heimerdinger magic he had in his first tenure with the team.