First a few veterans that I'm less confidant in than the Hines Ward group. These guys clocked in at around 800 yards in 08, their clearly on the downward side of their careers. Whereas I'm not turned off to those guys, these are players I won't draft, even if they put up some decent numbers this year. The futures are very dim, and at least one of them will probably put one more good year but I'm not willing to take the chance.
Now, some upside guys that should be filling out the end of your roster. Your 5th receiver should be a upset guy. In most leagues, unless someone slips, your probably taking one as your fourth wr also. You could consider this lost to start at the 31st ranked receiver, but in the end its a judgement of who has the highest upside.
The track record of third receivers moving to the number one spot isn't good, but someone has to catch touchdowns for Tennessee. I like Gage too, but Washington is the one with the high ceiling. Gage is more someone you pick up when you need a consistent options later in the season or possibly a third guy in a man's league. Washington is a deep threat with touchdown potential.
Hixon stepped in for Plaxico fairly well at the end of last season. The Giants are quite plug and play receivers, like say, the Saints. If the Giants don't make another move, Hixon is the guy who's value increases to a draftable level.
Another big name departure and another chance for a sleeper to take his place. The Cowboys will be a high scoring team once again and Witten will need some help. I liked Creyton before Williams arrived and I like him more now. Roy Williams and Miles Austin fall into this category as well, but Creyton is the one you should be drafting. It's possible Williams gets taken too early considering the lack of promise he showed last season. I have to admit I love Austin's potential but I don't think you need to draft him outside a very deep league. But keep an eye on him as the season progresses.
I like the Falcons offense overall next year, and while White really broke out in 08, i think Jenkins is the one who comes up this year as the reliable second option on a high-powered Atlanta passing game.
Johnnie Lee Higgins-Raiders
This is only a semi sleeper as he put up numbers last year and its possible the Raiders add another receiver, but Higgins just might be a star in the making.
A couple other quick names as potential sleepers. There are also a few teams(Bengals) that currently have no receiver options. If they don't make a move before the season, someone will have to be a number one. There are also rookies, who may have value in the right situation.
A few other names that I never mentioned.
I discussed Lance Moore a bit under Colston, and I do think he is the second Saint, but someone will pick him too high so there's no point thinking about where might be a good time to draft him. I like Devery Henderson in the 16 round better than Moore in the 6th. Chad Johnson might have value depending on where he ends up. There also could be value at some point in the season for Plaxico, but he will most likely miss enough games to go undrafted.