another thing that will make Zune especially difficult to hack is the fact it is closed format. Many devices, such as the iPod, require software to transfer music, but MTP players all use a similar structure so they're easier to hack once you have one. iPod's are, in technicality, UMS, as they appear as a removable drive on your computer. However, Zune's work only with ZMP, and thus more effort is needed to get into the meat of these suckers.
Another reason Mediamonkey doesn't support the Zune *sigh*