I had this idea while I was deciding which background I should choose earlier! Basically, I think it would be fantastic to have backgrounds that, possibly as well as fading slowly from one to the next and having slight movement such as snowflakes falling, also changed according to the time of day, or maybe even season or other factor.
I'm not sure if this has been done before, but imagine if as it got darker outside, your pc switched to the background you had chosen for night-time, and then changed again for the day!
For seasons, maybe a range could be stored online, and KDE could consult the online server which would give it a range of suitable backdrops.
Taking it further, maybe it could be used for topical backgrounds, such as if there is an event on that day. I think the possibilities are pretty fantastic!
We would need to think of a really cool sounding name for it though, mine was just an idea =)
Thanks for reading!
PS As a small idea of what I mean, I have included pictures of my desktop with images from the rather cool vladstudio.com (which gave me part of this idea). One is at night, and one is of rain =)