Hi,
when I first read about Decor8, first idea that came to mind is this:
How about the Option to have the backgrounf Image scroll with the tiles, BUT at a lower rate to create a sense of 3D?
Optionaly one could assign multiple Images which would fit together as a panorama Background, so the backdrop wouldn't have to be one very wide Picture.
You could even add some pics that would fit when repeated horizontally.
Just my 3ct 
-------------------- EDIT!---------------
Wheeeee!! Now that I got the download link and installed Decor8, I see that almost all of this is already there!
That's a BIG WOW - Thumbs up!!!
Andy