As cool as these sound, I still don't see the killer app here. If, as said, it's a movie/TV player and Internet surfing toy, forget it. I can see it replacing my laptop when it's time but I don't see me buying one in addition to a desktop, laptop and iPhone.
What I am thinking a killer app for a larger iPhone/Tablet would be is as a peripheral device for your primary computer... thnk of it as a "keyboard" from the future, completely customizable and that has actual computing power in addition.... oh yeah.. and on top of that, while you aren't using it as a peripheral it would also be the ideal personal media player available.
What I am thinking is that if you just try to market this Mac Tablet as a pure media device it seems kind of redundant to a laptop or even your primary PC. BUT if you market it as primarily an interface device that you use with your current computer.. be it Mac or pc then you have a killer app for this device. And this is on top of all the things it can do that the iPhone and iPod can do as well.
So when I say use it as a peripheral let me flesh that out a bit. let's say you are a film student.. and in your spare time you make a lot of student films. You know how there are those machines editors use when making films that have all kinds of buttons and sliders to make editing more efficient and easily controlled? They have the same thing for audio editors too.. like a big panel with all kinds of sliders etc.
Well.. the iPhone touch interface in a tablet form would be the PERFECT interactive canvas for making all kinds of customizable interfaces for this purpose. Any application you could think of you could have a custom control panel designed to use in conjunction with your primary computer. And the great thing about this is that rather than having this tablet that is JUST a low tier laptop.. instead you have something that can be used with your primary computer to make it more powerful and easier to use.
Basically, I view this as being an attachment for your computer, be it apple or PC, that makes it better and more usable.. whether it is by making a custom control panel with all different kinds of controls.. or as an input device for drawing OR just as a way of multitasking. Rather than having to upgrade our computer the tablet is a way of adding another monitor.. or another control method or just more RAM for multitasking.
So you could attach the tablet to your computer and it works in conjunction with it communicating and controlling it or working in tandem with it. Imagine you want to use your primary PC for some big task like rendering something.. your tablet could work in conjunction with your PC to play music so as not to sap your main computers resources. But what makes it so great is that it is connected to your computer rather than just isolated.
My only questions are whether Jobs WOULD do this.. would he make a device that works with Windows machines? And could he do this.. is it logistically possible to make a device like this that could work seamlessly with both macs and PCs as a peripheral for all different kinds of apps. If Jobs isn't going this route that I envision is it possible the Mac touch tablet could later be modified and customized for this purpose contrary to Apple's plans or in addition to them?