There is not one but two secret Xbox cats that Microsoft has kept in the bag. Currently there are three more Xbox 360 motherboards in the works right now. They are.. dun dun dun.. Jasper, Opus and Valhalla.
It's well known that the next Xbox 360 motherboard is going to be Jasper and it going to have both a 65 nm CPU and a 65 nm GPU. Jasper is going to be a major advancement in reliability since it is going to run much quieter than previous Xbox 360 systems. Jasper's reliability is in part to the fact that there is no place on the motherboard that is going to be running as hot or as much power as previous Xbox 360 systems, also it might run a lot quieter since it will not need as much power.
Jasper is very real and they are testing prototypes right now. Word from Redmond is that progress on Jasper is going well and on schedule and you can expect it fall of 2008.
The Opus project is a "Falcon" generation motherboard designed to fit in a Xenon case. You can expect an 90 nm GPU but a 65 nm 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.
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.
Now they are also in the very early stages of designing the fourth generation Xbox 360 called Valhalla.
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.
Microsoft has planned on near annual changes to the Xbox 360 motherboard generation designs.
First was the Xenon motherboard from 2005-06, then followed by the Zephyr motherboard 2006-2007, then the Falcon Motherboard 2007-now. Probably later on this year we will see the Jasper Motherboard 2008-2009. Then then comes Valhalla the year four motherboard in late 2009 or mid 2010.
