I don't think this is common knowledge.

The Zune 80 supports 640x480 TV Out but officially, the Zune 30 doesn't.
(The Zune 80 actually goes up to 720x576)

But......
If you do the Mass Storage hack which allows the Zune to be accessed through Windows Explorer, you can then put 640x480 WMVs on to the Zune.
No benefit if you're watching on the Zune (it can still only display 320x240) but if you use the TV Out, it will be ouputting the full 640x480 resolution.
The Zune 80, of course, does this all natively.

The negatives......
The WMV must be encoded using WM7 at 25FPS max.
Anything higher and the video will be all skippy and juttery.

And since you're not using the Zune software to sync the file, none of the metadata will transfer to the Zune -- not even the file name.

The video duration will transfer through Explorer so you will have that but otherwise, on the Zune itself all you'll have is a nameless file with no thumbnail. If your videos have identical durations you'll have to watch each one to find the one you want.

Outside of a dog -- a book is a man's best friend.
Inside of a dog it's too dark to read.

This seems to be a lot of work to get SD (i think) content on to a TV. I think this is evidence of MS walking a line between keeping content mobile (small file size, no more quality than the device itself can handle) and turning the Zune into a portable multiuser entertainment device. I think the two best ways to get around this are to get a DivX compatible DVD player or hook your computer up to the TV. Granted unless you have a laptop you lose portability and it's still bigger, but I think this is forcing the Zune into a role that it wasn't created for and would just seem to be a bigger headache than it's worth.

Forgive me if it seems like I'm putting your tip down, I do think it's great, just voicing my opinion of how practical it is. Thanks!