After playing with XNA I quickly learned I would need an actual Zune device (and likely a premium membership) to test and debug games and applications for the Zune.
After a quick search I confirmed that there currently is no Zune emulator. So the next trick is to learn the various models. My local retailers are selling; 4, 8, 16, 80 & 120 gig models and there appeared to be 2 form factors.
More searching and I discovered the following:
There is an older Zune 30 device which doesn't appear to be on the market
Also known as Zune V1
The Zune 4, 8, 16 are all based on the same hardware
The Zune 80 & 120 are based on the same hardware
So - 3 types of Zune so far.
All Zunes have 240x320 res screens
4, 8 & 16 are solid state drives - larger models have hard drives
Zune V1 has a 60Hz refresh rate, V2 & V3 are set to 30Hz (for battery life)
Zune V1 runs at 524Mhz
Zune V2 runs at 399Mhz
Zune V3 runs at 399Mhz
Time to go take one home