
The leaked information can currently be seen on the US Play Store when purchasing a Galaxy Nexus HSPA+ smartphone described as "soon the first phone with Android 4.1 Jell..." You get the idea.
Additionally, there's also an image showing just a bite of the visual changes present in Jelly Bean. That's a new wallpaper and a visually refreshed Google search bar on the homescreen. The picture is of low resolution, but still the changes are somewhat visible.