At first I thought it was pretty pointless, but I signed the petition because I think that the one they chose sucks, and the animal ones not only look great, they are also unique. We all know the waves, skies and landscapes from windows or Mac OS. But the animal thing is new. And I love the way he did it. They are usable default wallpapers since they are not distracting, and they are easy on the eyes (I could never use a picture or geometrical figures as wallpaper, it drives me crazy. Maybe I got some kind of ADD.)
Oh, yes... why this is important:

If you look for linux on google or google-video, you will inevitably get screenshots and compiz videos. Most of them on Ubuntu. Whatever is the default wallpaper will be there on video tutorials, on presentations, in magazines.

When I first used Ubuntu I was pissed off that they hid the boot log. I couldn't understand why they did it... But when I see the reaction of people watching my computer boot up without bootsplash, I totally understand it, and I think it was a vital idea. The first impression is very important.

Discussion on Ubuntuforums

The Pedition

On second thought I'm not THAT sold on the animal things... But the one they want to use now is a step back from the Feisty default theme, which is an excellent default wallpaper IMHO.
I like the idea of the anymal skins very much, but I don't think the ones in the link above are optimal (just tried them as desktop backgound).

Well I don't really agree with the idea that the default Ubuntu wallpaper has any bearing on the general perception of Linux because magazine articles will have screenshots of it.

That said, I actually like the brown wallpaper more than the others. I don't think the brown is great (they do make a good point, it is a little too dark for Compiz's shadows), but the other points they have against it aren't so hot. They cite the fact that it looks too similar to Apple/Vista wallpapers, but in fact that is the desired effect. The point of Ubuntu is to have a Linux environment that is not totally alien for Mac/Windows users, so having something completely outlandish for a wallpaper is going counter to that goal.

Besides, the point of default wallpapers is to provide something visually appealing without focusing on anything in particular that the end users might not like. For instance, you would never see a picture of a F1 race car as a default wallpaper, since not everyone would find that interesting or appealing. Likewise, not everyone likes animals or would want to see an animal print on their desktop.

I think their default wallpaper almost causes too much distraction. Anyway, that's a rule that can be bent I think. The suse 10.0 wallpaper being the perfect example. The biggest problem I got with their current default is that it looks out of focus. Which might look alright as a picture, but when you have it at 1024x1280 or bigger covered with icons... well some people don't care, but I can't look at that. It makes my eyes try to focus in vain.
Having tried the elephant one, I don't think it would be good either... also not enough structure. The lion one would be great - minus the logo. I didn't have any problem with the Feisty default. Even though I did not keep it, it integrated very well.

Anyway, I don't think they are going to change it, but it is something that many distributions don't pay enough attention to IMHO. Mandriva special addition... I think 2004 was a perfect example. The artwork was horrible. The fluxbuntu alpha has backgrounds on the gnome-terminal by default! Those are two of the worst artwork decisions I have encountered, and I do think it has an impact on the view people have of linux.
On the other end there is Suse and Fedora who have an awesome artwork team. It does make you feel more comfortable about the system. Even though I have had terrible problems with Suse, I still enjoy booting into JAD every now and then to monitor the progress, because everything fits together.

Jeezus Tap Dancing Christ. People who chose distributions or even chose to use Linux because of the default desktop look probaby shouldn't be in the user base anyway.

I think I started this topic from the wrong point... I stumbled across the wallpaper petition, thought it was kind of silly, but signed it anyway, because I thought they had a point. And since I've got entirely too much time on my hands I started thinking about it. And the wallpaper is of course just a tiny part of the whole picture. It is really about how the desktop is laid out graphically, and - don't get me wrong - I think the gnome and kde artwork teams are doing a great job making a very professional looking Desktop. But many distributions are making silly decisions on their own, without really thinking about it. Ubuntu Studio for example made a very nice looking gtk theme on the surface, but it made their bread-and-butter audio workstation (ardour) practically unusable. So in order to do anything comfortably you had to change it.
I personally could not for the life of me care the fudge less. I've been using Linux for half a decade, and I can change those things in a hurry. But many people will never ever leave the default option. Just look at how many windows desktops have the default wallpaper.
I think the graphical part is much more important than most people give it credit. Car companies spend millions on design, hell even sound and olfactory design. All those things enter into how you feel about working with a system. - Why would you put a rug in a room - same question really.