Press Release: Microsoft Announces Xbox 360 Price for Europe and North America.
The Xbox 360 Core System is $299.99 U.S./€299.99/£209.99 and there’s also a premium edition which seems to be just called Xbox 360 for $399.99 U.S./€399.99/£279.99. The Core System lacks a hard drive, wireless controller, and Xbox Live membership among other things. A variety of priced peripherals was also announced.
Update: Well, that’s what I get out of parsing the press release, but Todd Bishop has a somewhat different take based on other sources. His feature list has the Core System including an Xbox Live subscription but lacking backward compatibility with original Xbox games. The latter isn’t even mentioned in the press release that I can see. I’ll update this again when the details get sorted out.