I know the current iZ3D driver has a side-by-side output format (left/right or up/down).
It is my understanding that this in not exactly what is defined as HDMI 1.4 frame packing formats (720p@60Hz = 1280x720 per eye or 1024p@24Hz = 1920x1080 per eye), but e.g. 960x1080 or 1920x540 per eye for an output resolution of 1920x1080@60Hz.

So here is my questions:

Do the new 3D HDTVs (especially the Panasonic Plasma VT20 or new GT20) understand the side-by-side output of the iZ3D driver and produce a 3D image?

The iz3d driver does not work with HDMI 1.4 at the moment. Hopefully they will do this in the future, but it doesn't work now. However many modern 3D HDTVs support side-by-side format (which is what is used on broadcast TV, for example) so you should have no problem using the iz3d driver in side by side mode. I am pretty sure the Panasonic VT20 supports this, not sure about the GT20.

I'm able to run the iZ3D drivers on my Panasonic 3D HDTV. The Panasonic televisions handle squished side by side mode - you just have to turn it on via the remote control (Viera Tools).

Regards,
Neil