The AfA-OS Zune backport works reasonably well, with a 'promoter' tool required to be run in the background in order to redirect MUI calls to Zune.
There are still a few bugs to be ironed out, and some tools I used refused to open correctly using Zune, although this may simply be because the programmes in question were not written for absolute MUI compliancy.
My suggestion would be to simply experiment with the promoter and play with real gradient backgrounds

Cheers,
James
x