This website, comicbook.com, was the first to discover this before anyone else noticed it. The first “Dark Knight: Rises” poster where we see Gotham City crumbling and falling apart, you see the Superman S shield on one of the buildings.
In the new “Dark Knight: Rises” poster with Bane, you see a mysterious hidden face that could reference Henry Cavill as Superman. You can see the mysterious Superman face slightly beside Bane’s head in the poster.
I’m sure many of you would call it a fake and photoshopped but if you look at the “Dark Knight: Rises” official site, the mysterious face is still there. The mysterious face was definitely put there intentionally. Is it Superman’s face? Probably, because the way it is shown it is shaped like an S shield. If you look at the vertical version of the poster here, you see the mysterious face in a different position, it’s between the letters “E” and “G, in the word, “Legend”.
What’s with all the Superman mysteries in the Batman posters? Could this mean that Superman is in, “The Dark Knight: Rises”, in some way? If so, that would be pretty fuckin’ cool, if Superman was in “TDK: Rises”.
It doesn’t surprise me that Superman could possibly be appearing in the next Batman film, since both the new Batman and Superman movies are being made at the same time. Batman and Superman have teamed up for years in comics and animated movies. It’s time to team them up in a live action movie, which was long over due.
Kev
K'Brocking 
Nolan didn’t add Robin because it would ruin the way he wanted to tell the story. He doesn’t want it to be viewed as such pathetic remake but a new well made Batman that we don’t know and that we should know. Adding Superman here would give d*mn sh*ts to the viewer ‘case Bruce Wayne would never figure himself out alone. So does it mean now that Superman’s gonna save the day for him? I hope not. I hope the man behind the mask would rescue himself. Just himself.
I hear ya, I really don’t want Superman throughout “TDK: Rises” myself, it should be a Batman movie, but a tiny Superman cameo would be nice though. Maybe they’ll have Superman give Batman a piece of advice, maybe that’s about it. – Kev