Now it is reaching out to Japan and Australia. Of course Japanese version will support Japanese language.
The new launch also allows to publish YouTube content and just like AdSense ext and image advertisements you can choose by category, from particular publisher or automatically. But if you want to promote your own videos, you will have to sign up as a YouTube Partner.
To set up video units on your site, log in to your AdSense account and visit your AdSense Setup tab; if you have a site in one of our supported countries and languages, you'll see the option to set up video units.
Of course you can go for help at anytime, at AdSense help.
Here is the Video helping you out!
Inside AdSense: Video units now available in Australia and Japan