I don't think there's any doubt that Hines Ward will play in some capacity in the Super Bowl. No matter what his capabilities are, it's a contribution to the team. I mean, who else are they going to throw to besides Santonio, Nate and Heath Miller? Limas Sweed? I think he's (along with Arians) is the Steelers counter to Matt Leinart for "Asshole least deserving of a Super Bowl ring".
Anyway, for a receiver or a back to completely rebound from a sprained knee in two weeks is going to take a minor miracle. I have no doubt he'll play most of the game, but how much of a factor can he be? As Baltimore showed, without Hines, the offense is pretty easy to stifle, especially when the running game isn't doing shit. If Arizona can get ahead early, and I imagine they'll be employing a lot of Whisenhunt trickeration to do just that, I have serious concerns about the passing game being able to keep pace.
We all know Hines is going to do everything it takes to rehab the knee, but what contingencies does the offense have if he's not all the way back?