Next Xbox 360 motherboards codenamed "Opus and Valhalla", says rumour
Says so here.
"The Opus project is a 'Falcon' generation motherboard designed to fit in a Xenon case. You can expect an 90nm GPU but a 65nm CPU. Opus solves a major hardware recycling and inventory problem since Microsoft currently has millions of used Xenon cases from RRODed dead systems and this lets them use most of the good parts from the millions of dead Xenons but with a newer tested more reliable motherboard," said Jacob Metcalf, a man with an apparently good source at Microsoft. "There is no HDMI on Opus since the Xenon cases don't have openings for the port. Opus is a third generation Xbox 360 in the case of a first."
He continued: "At the heart of a Valhalla Xbox 360 is a combined 65nm CPU and 65nm GPU on a unified super chip. This also would only need one cooling system and be much quieter and hopefully more reliable than previous Xbox systems (if they include hardware JTAG testing reporting into the design).
"It is really early in the design process but there are engineers at Microsoft working on it as you are reading this. Heck they are probably reading this since this is the first that you are going to hear about Opus and Valhalla.
"You can probably expect a price cut for Valhalla since it is going to be a major cost reduction."
Rumour with a capital "R".