As the previous response said, you can't burn your iTunes movie to a DVD. The Apple TV will be a great option but you have others as well.
The easiest option is to use the iPod Video which can connect directly to a TV's RCA jacks for video output. If you have an iPod Video then you simply need to buy a cable and you are ready to go--easy and portable. This is great for hotel rooms!
Another option, depending on your computer's and TV's input/output jacks, is to connect your computer directly to your TV. I have an inexpensive Windows XP mini-tower equiped with a cheap dual monitor video card that allows me to output composite-video, s-video, VGA and DVI. Some cards also support component video.
If this sounds to complicated, and you have a widescreen TV with component video inputs, then I would wait for the Apple TV.
http://www.apple.com/appletv/