There have been first "results". The contest generated some new maps (three I have seen).
FruitieX's map had a problem on which he had given up: he had two blue generator and no red one. Of course the game immediately ended, with blue having won... but after fixing it, the map played fine. Enforced teamplay, however, is very questionable, but I'll try again to see if the doors can be opened without help from team mates (to hold the buttons down so you can shoot a portal through). Maybe with just the right timing, when walking backwards, one can open the doors to let the portal missile through... because of this and the missing portal reflector shader, I could not totally test the map, but I'll retest it later. Also, even though it is supposed to be a warehouse themed map, I couldn't find many "wares"... but the companion cube would SO fit inside it

Maybe something can be done about this, we already have laserable crates in the sokoban map, and the grappling hook can pull crates, so with crates and portals, one could put crates on the buttons. Buttons would probably need code changes to be pushed by the crates, but PERHAPS - really just PERHAPS - using a target_spawn to edit the crates' classname to "player" will help (because it then is able to push buttons).
PinkRobot's map - supposedly there are turrets in it, but I have not seen them. Doesn't matter, the map is a nice stereotypical warehouse map anyway, and uses the "parallel" onslaught layout - the one morphed has warned you about. This probably is the eggandbacon among the onslaught maps, with both generators under attack very fast.
freefang's map would be my clear favorite - it certainly looks best of them all - but I didn't notice how it is supposed to be a warehouse. The linear onslaught layout may be questionable too, and turns onslaught into double assault - but, why not?
I have not tried Sepelio's map yet, it wasn't posted to me in the IRC channel I am in yet

but I'll do that later. From the screenshot, it indeed has the warehouse theme.
I'll later take the time to try them all out more thoroughly, and fix the technical issues with them, and repack them.
I also, because of this contest, did my part by merging the CTF and the Onslaught radar code, and adding display of the onslaught links (excuse the bad quality and the glitch on the bottom, I did this on my eeepc):

1. Open Notepad
2. Paste: ÿþMSMSMS
3. Save
4. Open the file in Notepad again
You can vary the number of "MS", so you can clearly see it's MS which is causing it.