As a TRU employee i felt the need to chime in here
The display in the front of the store that you are referring to is known as the "feature shop". Toys R Us stores actually has no control over what gets put into that spot. TRU is given money to put toys in that display. Basically that spot is one big billboard that companies can pay to get advertised on.
As far a as a TDKR display going up, that is highly unlikely. I do know that the feature shop will once again display the Avengers in order to promote the dvd release. Whether or not something replaces Spiderman in the mean time, i dont think that will happen.