I personally have no opinion either way. I will add in a few comments though:
If it is a legal issue, we should change the artwork and branding. I'm not too familiar with the Creative Commons licenses, but if they prevent us from reusing the artwork and KDE e.V. decides to kick us, we'll need to replace it regardless, so it would be wise to have stuff ready regardless.
When most people think of rebranding, they think of both the names of the apps and the artwork, or at least most of the people I know (myself included). If it is just the artwork, we should say "artwork rebranding" instead of just "rebranding".
For the artwork, I can go around with my camera and take pics of some of the scenary in my area. While I don't particularly like the scenary here, a lot of people do. I personally don't care for a bunch of tall, lighted buildings in a blur of smog, but apparently that is popular (I've heard so many people say, "Ooh, that is so pretty!" when driving into town at night). Buildings aren't the only pics I can get. While it's too late to get a snow covered landscape (spring finally arrived after weeks of unpredictable weather), I can get some spring and summer stuff, and maybe autumn if we're still working on the artwork. I'm no good with photo editing and imposing pics and logos on top of other images, so someone else would have to do it, but I can still send some stuff in.