Update: HardOCP has reported that a Chinese site got their hands on some spy pictures of the new Xbox Elite. These pictures (dated 02/14) don't really offer a detailed view of the new console, but are definitely interesting.
The black Xbox 360 is more than just a rumor now, it seems. Dubbed the "Xbox 360 Elite", Microsoft is planning for a limited-time release towards the end of next month. On top of being black (I suppose that makes it all the more cool), the "Elite" console will sport a 120GB HDD and an HDMI output interface, but will not support HD DVD playback. While Microsoft denied rumors of a HDD upgrade for the console a while back, it seems they'll also be offering an expansion HDD for the 360 for around $200. That's more than pricey for a 120GB HDD, but even the "Elite" versions end up coming in below the PS3 at $479.
After a short while, they will go back to using a white chassis, and the newer console will phase out the Premium version of the 360. It is interesting to see Microsoft creating new iterations of the 360 while still keeping the same core console, something that we have not seen much in the past. Their willingness to do that might let them keep up with newer consoles that may come stock with Blu-ray or HD support.