The new xbox is going to be released in March 2007. It will sport the 65nm cpu chip and may be sold in black only. Not confirmed if it will be sold in both colors yet. And no it will not have HD-DVD built in. THey are making a killing on the HD-DVD add-on.
Also with DirectX10 hitting next month or 2 you can bet your sweet a$$ that Microsoft,Sony, and Nintendo are going to be designing some sick machines for 2011.
Source? I've heard no news of a new Xbox 360 anywhere.