I've had a few days with the Zune, and so far I like it. I do miss some of the "auto-generated" lists that the old GigaBeat inherited (Songs by decade, recently added, etc.). From what I've read that stuff was all in the last version of the software, but the most recent version removed it - not quite sure why. I'm ok with apps having a "simple to use" interface - especially if they perceive themselves as competing against companies such as Apple who prides themselves on being so "simple to use" they're almost useless, but for Pete's sake - leave in the OPTION of going to an advanced interface for those of us who want a bit more.
One thing I do love is the "Zune card" which - whenever you sync your device - updates the tracks and songs you're listening to. My Zune card is below the blog list - you can see what I've been listening to of late, and check out the faves I've marked. This is similar to the "Xbox Live" gamer card tag, and a great addition. They even have a facebook gadget designed to allow you to embed your Zune card in your profile - very nice.
I also tried converting a video ripped from my Tivo to the device. I downloaded a 1/2 hour TV show and converted it to the 320x240x30bps wmv format that the Zune plays back. The playback was very good - not grainy or hard to see. Words in credits of course were almost impossible to read, but in general the video and audio quality was excellent. The conversion time was pretty long though - you can do all the stuff in the background while converting but it does slow your machine down (I used Roxio Media Creator 10 to convert the video). In general if you have time to convert, you probably have time to watch it :) If I had more energy I could probably set up a machine to just "bulk convert" stuff that was ripped and that would take less time, and free up my laptop for other things. Of course having more time is like - yeah right :)
In general though I love the new player - nice headphones, good response time, very nice "touch sensitive" scroll and volume control without having to gum up the screen with my greasy fingers (the touch sensitive part is on a "dpad" like controller). And Microsoft has announced the possibility of mobile games to go with it. So far battery life has been decent, though you need to remember to turn off the wireless if you're not using it.