Its assumed Mike Wallace is gone, but I don't know if thats for sure, but it looks that way. Even having his worst season as a Steeler, he led the team in receptions and I think TD's as well.
If Mike indeed leaves, the Steelers might want to get aggressive in the FA market, but a replacement won't come cheap unless they just want another body.
I would strongly consider Dwayne Bowe of KC, he isn't happy there and you can't blame him, with a better QB like Ben he would flourish in our offense. At 6'2 215 he's a big target, and the physical receiver fans have been talking about, but it will come with a price.
Can they find a way to even consider a receiver like him? I don't really know, but if we let Wallace walk your letting your most productive receiver go even if you don't agree he is.
Wallace proved he can be a tremendous receiver for us outside of this year, but even Brown had a bad year, so there is still a slight possibility the Steelers could work out a deal. He won't command the money he wants, and with a decent deal here he may elect to stay.
Either way, signing Mike or Bowe won't come cheap.
I know most fans are disappointed how this season ended, the Steelers front office is too, but they should be pissed that we had one of the best defenses and sitting home for the playoffs.

There is talk about releasing players and how it will effect our cap, sooner or later we will be in a bind because of it. Sorry but the Steelers need to remove unproductive players and ones that are in the tub every year.