It seems a handful in the Twitterverse have already discovered, but in case you're among those not in the know, so to speak, Microsoft has rolled out firmware 4.5 for the Zune HD. To recap, that includes Smart DJ mix, personalized recommendations, Marketplace support for TV, and expanded video codec support, a number of those features you can see in our hands-on piece (video embedded after the break). As usual, the update runs via the Zune desktop software, so plug in and enjoy!

[Thanks to everyone who sent this in]