Even with the announcement of the Xbox 360 Elite, it seems the longstanding rumor of an HDMI adapter for the regular Xbox 360 just won't die. An Engadget reader named Evan M supposedly sent Microsoft an email after learning of the HDMI enabled Xbox 360 Elite. You see, Evan just purchased an Xbox 360 Premium, and was understandably miffed on hearing of the new Elite, knowing that his television supports HDMI. Evan received a response from Microsoft stating that a component to HDMI adapter was in the works, though the support person was unsure if this device would ever be sold by itself. In other words, it could be sold with a future iteration of the original Xbox 360.Now, customer support isn't always on top of everything, so the information can't be taken as gospel. Furthering the doubt of such an adapter, Microsoft's Andre Vrignaud, better known as Ozymandias, recently stated such an adapter is not in the works at all. Furthermore, Ozymandias states that a hardware change was required to implement HDMI in the first place, hence the creation of the Elite.
And of course, the most obvious reason to doubt an HDMI adapter, it would serve no purpose. The analog-to-digital conversion created by an adapter would likely nullify the enhanced visual fidelity of HDMI anyway. Unless the HDMI port is the only free port on the back of your television, an adapter wouldn't make any sense at all.
