Are "Opus" and "Valhalla" the next, next Xbox 360s?

Although word on the street is that Microsoft is planning to release the successor to the Xbox 360 in 2010, the company is still apparently planning on updating the 360 design several more times in the next couple years. Just like the "Falcon" motherboard now on shelves updated the original 360 design with a 65nm CPU, the upcoming "Jasper" revision should take the GPU to 65nm as well -- but that's more or less common knowledge. What we're hearing now is that all those RRoDed 360s sitting in warehouses are going to be retrofitted with the same 65 / 90nm CPU / GPU combo as Falcon, but on a mobo design called "Opus" that fits the original Xbox case molds. That means no HDMI, since pre-Falcon cases didn't have the openings -- but apparently MS is only planning on sending these out as warranty replacements. The real action, however, appears to be "Valhalla," a supposed final rev of the 360 that integrates the GPU and CPU into a single "superchip." Details on that are more than sketchy, and we're definitely skeptical -- especially since we'd been hearing chatter about 45nm CPUs, but nothing about a unified architecture. We'll see when we see -- as long as all these boxes play CoD4, we'll be happy.