Amazon’s video download service, Unbox is live. And it’s Windows only.

The Unbox System Requirements say: “The Amazon Unbox video player is not compatible with Apple/Macintosh operating systems.”

Note that they’ve anticipated Intel Mac owners trying to get into Unbox with Windows-on-Mac solutions like Boot Camp and Parallels; another note says: “While it may be possible to run the Amazon Unbox video player on an Apple computer running a required Windows operating system, we cannot guarantee performance on those systems.”

I’ve not yet seen any posts from anyone who’s actually tried this, but I’ve no doubt there’ll be some appearing online soon.

The main reason I’m mentioning this here is because of all the hoo-ha in recent days about next Tuesday’s “Showtime” event and what it might portend. Clearly the smart money says it will be a video download service, and obviously that would mean direct competition with Amazon.

But given the cross-platform success of the iPod and the iTunes Music Store, I’d be astonished if Apple launched a video version that was Mac-only.