I haven't logged in to post in ages. Just scour the forums and read everyones posts everyday. I had to reply to this because I absolutely agree. The Zune HD interface is phenomenal. Initially, I thought the Zune HD interface on the Droid would be impossible (because the Zune HD uses the NVidia Tegra processor). However, after rooting my Droid, having it OC'd and running 3's music player a few times (looks fancy, the practicality of it is limited), I think that the hardware limitations of the mobile processor aren't as much off as initially feared.
Basically, if someone can design an app that mimics the Zune HD's interface, they will have my money (hell, I'll pay AT LEAST $5 from the Marketplace for it) and I'm sure it will sell like hotcakes because there is nothing on the Marketplace that comes close, as far as music players go. There are a few that aren't bad but the Zune HD's interface takes the cake. I've been running the Rhapsody beta since it launched a couple of months ago and though it's nice, it comes nowhere close. I'd love to have an end all device but as it stands, I have to drive around with a mess of gadgetry to get the end results I desire.