This is the surprise Kojima Productions was teasing last week at the Metal Gear Solid HD Edition official site:

The girl in the video is Haruna Kojima, a member of pop group AKB48. Kojima Productions has tapped her for the Metal Gear Solid HD Edition promotional campaign.

All the "Spring has come to Kojima Productions" nonsense from the teaser site was just a play on Haruna's name. "Haru" is Japanese for Spring.

View the official site here for pics and, eventually, additional videos.