In this article, Mercury News writes:
"Microsoft didn't want you to know about Falcon, and it certainly doesn't want you to know about its successor Jasper. But that's another secret we have to unveil.
Jasper is the code name for the next motherboard for the Xbox 360. It will becoming next August, in time for next year's holiday season. Jasper is going to have a 65-nanometer graphics chip from ATI Technologies, as well as smaller memory chips. That isn't much information, but it's enough to tell us about their cost-reduction plan. If you ask me, it's a bit of a slow pace.
I don't know why it will take Microsoft essentially three years to cost reduce the size of the graphics chip through a manufacturing shrink... Microsoft has had to divert a lot of engineers to debugging problems with Xbox 360 reliability. Even so, you would think that they would have moved faster, since the move to 65-nm graphics chip will likely be one of the best things they can do to improve the reliability."