It wasn't really a rumor in the first place, as evidence of Skype on the PSP popped up on Sony's official Consumer Electronics Show website. However, we could always use more confirmation, even if Sony hasn't officially stepped up and revealed the new feature.
According to GameSpot, Japan's Nikkei Net news service has reported that Skype functionality will indeed be added to the PSP "as early as this month." Nikkei took things just a step further by filling us in on some choice details: Skype, the Internet communication/phone technology service, will only be available to users of the PSP Slim, which only recently released last September. If you own the older model, you can still download the Skype software to the PSP, then utilize a specifically designed microphone. Oh, and the service will be free for PSP-to-PSP and PSP-to-PC calls. An estimated cost of 2,250 yen (about $20.70) was given for three months worth of a dedicated phone number.
But once again, Sony remains silent on the issue. Chances are, they're just waiting to unveil it at CES 2008 next week, and aren't about to let the cat out of the bag just yet. But as far as we're concerned, the cat has already escaped, eaten a hearty dinner, and is currently dozing on a warm blanket by a roaring fire.