One model is reported to be the long-awaited full Video iPod, but Steve Jobs has "so far been unwilling to commit the marketing and other resources necessary to bring the device to market" until the market response to the iTunes Movie store and iTV can be better gauged.
Which I'm guessing means that the iTunes Movie Store hasn't been a runaway success... yet. Not that I would expect it to be, until the iTV is out and some more studios sign on.