It's a couple of weeks late, but the Apple TV software update is now available to the public. The free download updates the Apple TV with a variety of new functionality presented at last month's Macworld show, including HD movie rentals and PC-free access to the iTunes Store.
We're downloading it now, and will be reporting back soon with some hands-on impressions. In the meantime, check out Steve Jobs' preview of the new features.
UPDATE 2: Full hands-on review and video available here.
UPDATE: My initial impressions are pretty positive. As far as the new features are concerned:
Onscreen iTunes Store access: The new main menu uses a split-screen navigation--primary selections on left, submenus on the right. Access to iTunes Store content (movies, TV shows, music, podcasts) is not unlike the iTunes desktop software, with featured and most popular items called out with box shots (see above), and the ability to drill down farther using alphabetical search via an onscreen keyboard.
Movie rentals: There's a limited selection so far, but the process works pretty seamlessly. Click on the movie of your choice, get an onscreen summary (with an available video preview), and just click to rent. HD videos were available for viewing within 45 seconds of ordering--though it's worth noting that we're on a corporate T1 broadband connection.
Video quality: Scenes from Ratatouille and Transformers demonstrated that the HD video quality is far superior to the previous low-res offerings on iTunes (which were optimized for the small screens of the iPod/iPhone portables). Foreground detail on both films was generally impressive, with (for instance) the fur of the rats in the Pixar film clearly apparent. But the compression needed to get the films into streamably small file sizes is evident: Backgrounds still exhibit MPEG artifacts, and fading into and out of black show noticeable solarization. In other words: It has the same strengths and weaknesses that we've seen on downloadable videos on Vudu and Xbox 360 Marketplace. Most viewers will be suitably impressed, but videophiles will be able to see bandwidth constraints that fall short of the best Blu-ray movies.
Flickr and .Mac access: Access to these online photo galleries worked perfectly. Public galleries are accessible just by typing in the account name--including slide shows with the Ken Burns Effect and background music (the playlist of your choice).
So far, so good. I'll be updating the full review soon. In the meantime, if you've got a specific question about the new Apple TV, ask it below, and I'll do my best to track down an answer.