With the original Z30's the in-store demos worked great. However, with the release of the v2 models I have yet to see a working demo in any store, including Best Buy. I have yet to even see a Z80 at all. All the stores I have been in only appear to have the Z4 and Z8's available. This is in the Dallas/Ft Worth area.
To be honest, I seriously doubt I would have ever bought a Zune if I had to rely on the store displays I have seen. Even with the original Z30, most displays were hidden at the end of the aisle, behind a counter, if out at all. One of the biggest disappointments I recall was my local Best Buy. Even when a Zune rep was there to display the units they had him in an aisle one over from the rest of their MP3 players.
What is really sad, is probably the best display, and biggest selection of accessories, I have seen in the past year was the one at our local CompUSA during their store closing sale. Second to that would have to be Office Depot as they generally have one or more out on display with their other electronics.
Red Zune80 / HTC Tilt 2 / Nook / iPad 16GB WiFi