I received a local press release from Sony today. That means it was in Czech so I’ve translated it for everyone who doesn’t speak Czech:

If you buy a PSPgo before the 10 January, you can choose between the ultra-realistic driving simulator Gran Turismo for PSP, brutal off-road racer MotorStorm: Arctic Edge or scary action adventure Assassin’s Creed: Bloodlines, and establish your games collection. Just bring your PSPgo home, establish an account or log in to your account on the PLAYSTATION Network (via the PSPgo we assume). Visit the PlayStationStore to download a special item. This will generate e-mail from the PlayStation Store, including an electronic voucher with a promotional code to download your chosen game. This offer officially applies from 1 December to 10 January, but due to the upcoming holidays SCEE has extended this offer to everyone who has bought PSPgo.

So it looks like all PSPgo owners can get this deal by signing into the PSN Store via the unit and downloading the special item code. Good luck and let us know how it goes. I’m not sure at present the full extent of this promotion in regards to coverage area.