Apple's own Mini DisplayPort to Dual-Link DVI Adapter—the one you use to connect a Mini DisplayPort to a 30-inch display—has problems. These problems were never fixed with a software update, unfortunately. But Kanex thinks they can do better.
The dream of putting HDMI content (Blu-ray player, Xbox 360, PS3 or even another computer) into a 27-inch iMac has FINALLY come true. Kanex, who have done MDP to HDMI adapters, now goes the other way with the upcoming accessory.
Frustratingly, Mini DisplayPort doesn't include audio, so to get sound when outputting to an HDTV using HDMI, you'd need to use yet another cable. This adapter uses USB for audio, so you get the full A/V with just one cable.