The winners of the Ubuntu 15.04 Vivid Vervet Community Wallpaper Contest were revealed yesterday. The new wallpapers didn't land in Vivid yet, but you can already download them via Launchpad.
Download
The images above are small and for presentation purposes only. These wallpapers should land in Ubuntu 15.04 Vivid Vervet soon but if you can't wait or you're not using Vivid, you can download the full size Ubuntu 15.04 Vivid Vervet community wallpapers by using the link below:
Note: the zip archive linked above contains an archive that doesn't have an extension. After extracting "WallpapersV2.zip", rename the extracted "WallpapersV2" file to "WallpapersV2.tar.gz" (so add the .tar.gz extension) and then you'll be able to extract it.