As we know, earlier in the month NVIDIA invited hundreds of editors and affiliates to San Francisco to unveil the company's latest card, the GTX 680. Still under NDA at the time, we didn't learn about the meeting until last week, but it seems the GTX 680 wasn't the only thing unveiled. Information has leaked that NVIDIA is currently developing a desktop CPU, which will act similar to the upcoming mobile CPU, Tegra 4. Currently being called Tegra-D (presumably for desktop and not decongestant), this will mark NVIDIA's first foray into the desktop CPU market. Seeing as the company's main graphics card competitor, AMD, also has a stake in the CPU market, this seems only logical. However, it'll be interesting to see how Intel reacts to the news.
Exact specifications of the Tegra-D have not been released, but sources have said it'll act similarly to the mobile Tegra chips in that it will be a quad-core CPU with a fifth companion core. The fifth core will be used to handle background processes while the rest of the cores handle the boatload of the work. NVIDIA says its drivers will have the instructions for the fifth core and the company plans on pushing out frequent updates like it does for its graphics drivers. As of now, there are no plans to allow end users the ability to control what the fifth core is used for and it seems like it will be locked. NVIDIA did state that the fifth core is completely independent from the other four cores, so that overclocking the main cores will not be negatively affected.
Aside from developing a desktop CPU, it's probably safe to assume NVIDIA will be re-entering the motherboard chipset market. For those that have been building computers for awhile, you probably remember that NVIDIA chipsets were quite popular, so it was a shame when the company stopped producing them a few years ago.