Wondering if any of the notebooks have an HD panel in the seven inch form factor. I found some DisplayPort information and it looks like Apple is an early adopter. This would allow the notebook to double as a small monitor for use with a Canon HV20 or 40.
I think you might find the port is output only.
The ideal thing would be to run DVRack however that's hard to come by these days, you would need a firewire port on the laptop and a 7" laptop might lack the grunt to run HDV in real time.
If you want full HD I don't think there's one available that has that res screen with that small a form factor - just got a netbook and it's 1380x768 if I remember right. That's the highest res screen I have seen on a netbook and it's larger than what you want. In this size you can get several that run Win7 64 bit with up to 4 gb of ram and enough processor to keep up with You Tube HD content smoothly.