Which Steeler receiver makes the three sideline catches Boldin makes? I don't think any, Boldin has been a security blanket for a quarterback that played great football during the playoffs, combine that with Boldin just completely dominating defensive backs during the playoffs and you have a good combination. Joe could make risky throws and the deep one down the sideline while on the run was extremely risky, but he knew Boldin would at least make sure it isn't intercepted.
The Steelers don't have a WR that is remotely capable of making a play like that, let alone 2 or three per game. I won't be too sad to see Wallace go and hopefully, 1.17 or 2.48 brings a physical receiver or a TE that can get down field like Vernon Davis to the Steelers to compliment Brown. The Steeler receivers need Ben to be perfect with his throws to be successful; he won't always be perfect as we know.
This is a great point. The Steelers really need a WR who can fight for a ball and win the battle consistently, even if they are not open.