According to 9to5Mac, Apple will be including a set of four new wallpapers for its iPad version of iOS 5.1. Many of these wallpapers are scaled down versions of those found on Mac OS X Lion, in order to match the resolution of the iPad.
It does not appear that Apple will be releasing these new wallpapers for its iPhone and iPod touch versions of the upcoming iOS update. Fortunately, 9to5Mac has conveniently resized the new wallpapers for use on the aforementioned devices, available through the source link.
All of the new wallpapers can be seen in full size by proceeding to the comments section for this story.