I don't think the company is around anymore. Prismic works be it very slowly, but as for wallpapers, the site doesn't update them anymore, (or I haven't noticed any amazing new wallpapers available).
To be honest, I gave up with that website ages ago. I would recommend checking out http://interfacelift.com/wallpaper/downloads/date/any/ and downloading the 800x480 (Netbook) wallpapers- this is the perfect size for my Nokia N900 and there are thousands of photos on this site to choose from. e.g. Monument Valley Drop into a folder off your /home/user/MyDocs/ and then use Prismic or change background to swap your wallpapers. - works like a charm. If you have more than 4 desktops, then I would recommend using Maemodder.