Ubuntu design team member John Lea had this to say:
“We have got the 13.04 wallpaper ready ahead of schedule, so we might as well get it in the distro now”Well, what does the wallpaper look like? It's below. My first thoughts on this, not to bang on Canonical or anything, are that it looks like the 12.10 wallpaper turned upside down, with minor visual changes. I hope Canonical can do better than this though. But hey, they have months to go and I hope they improve the wallpaper before 13.04 gets released.
If you want to grab the wallpaper, you can do so by clicking the button below.