Umm I may be a little slow but - by jailbreaking do you mean there is a way to get free vids ? could this help me in Australia?
If by "free vids" you mean somehow getting any of the movie rentals from iTunes for free, then the answer is no.
By "jailbreaking" your Apple TV, just like with the other "i" devices, you will be able to install 3rd party software, such as the reason why I was so excited to buy and jailbreak an Apple TV to begin with, XBMC!
I've went ahead and jailbroke my ATV, and unlike what someone posted, I am not experiencing any lag whatsoever, the whole thing is running very smooth, I really couldn't be happier. I love it!