If we're not going to trade for a good WR, then we'll have to go the draft route or the FA route. Houshmandzadeh would be an awesome signing. A couple guys I'd look at would be Bobby Engram and Amani Toomer to keep a reliable veteran presence in there and offer Hester/Bennett an opportunity to better themselves. Via the draft, guys like Jeremy Maclin and Percy Harvin would likely be there in the 1st round when we pick, both would be good selections.
Realistically, we could overhaul this WR core by going out and getting a stud (Boldin/Houshmandzadeh/Johnson) and drafting a WR early. I'd imagine something like...
Johnson/Houshmandzadeh/Boldin
Maclin
Hester
Toomer
Bennett
would be a very nice WR group with potential to be awesome. I wouldn't be opposed to keeping Lloyd. He was pretty impressive early in the season before he got hurt. I'd also like to keep Davis but only as an injury replacement or special teamer.