"whether the itunes streaming software is compatible with the TV. If it isn't now, it may well be in the future."
I would never bet on Apple opening up their iTunes security to any other third party, it's just not their way and to the best of my knowledge with the exception of a flop of a phone a few years ago they've never done it. So the chances of iTunes ever being able to stream protected video to other devices is, in my opinion, pretty slim.
"I thought the apple tv thing would connect to my tv? "
Yes you could use an Apple TV and that would make things all very nice and simple, as is the Apple way. However as is the Apple way you'll also pay for it. However for the price of a few cables, which will be a lot cheaper than buying a new gadget, you could just connect your laptop to your TV and watching things straight away.