I wouldn't be very interested in this, except that television tuners and handhelds have advanced enough that this unity might work and be very successful.
I also see it as a great alternative to the PSP and watching DVDs or their own little DVD movies for that system.
If the technology is there to keep a solid television signal while on a car trip I can see this as a very exciting proposal.
For the low price of $250 dollars I can get a portable game system and television.
I hope this turns out very good. I don't know how likely I would use it since I don't watch tv, but for others its an interesting idea.