I don't use Deskscapes, but I downloaded High Mountain Lake Flowers, and it took about 35 seconds, not too bad. I didn't think that it took too long, considering the fact that it's really a small, miniture video. Of course, it is going to take longer to download than a CursorFx file, or a Windowblind, or a Wallpaper. I thought that the download speed was acceptable, and it didn't bother me. Have you tried a different browser to see if this problem persists? Also, sometimes when people have a lot of applications open in Windows, after a while, things lock up and slow down or sometimes even freeze. In order to get back to business, and speed things up, you need to shut down Windows and reboot. That may not be what's causing your issue, however. What version of Windows are you using? You can use Winver in order to find out. 

Just my opinion here, but as you probably already know, there are several things at play here.

The server setup and age of equipment; the size of the file; and the traffic on the site at the time of the download.

As 3java3 said, I find that download speeds are acceptable, all things considered. They might not be as fast as other sites, but considering the wealth of art available on WinCustomise, well worth the wait.