Yes, there will be posters there, along with other stuff such as athletic equipment, etc. Expect a ton of people and a not very good setup to get around to the various players, but it's pretty fun.
They usually end up having the linemen and less popular players sitting in a big line which you can take your poster too and they will sign it and pass it down the line to the next guy. The popular players try to get over there, but they always get stopped by fans and end up having big lines around them wherever they get stopped.