Soon.

Just wait until the the new 65nm 360s come out. (Which should be around December.) That or you could buy the Elite or the Halo 3 edition. (They both have revised mainboards, with the most notible change, a HDMI out port on the I/O board. The Elite runs 479.99, but you should be able to get the Halo 3 edition for cheaper, as it only has a 20GB HD instead of Elite's 120GB HD.