http://www.square-enix.co.jp/0706/

It's the new Squeenix countdown teaser... If you turn up the volume you'll hear an epic 8-bit tune that I sure haven't heard before... is it from the Dragon Quest series or something?

I don't recognize the music, and no site I've checked knows what it is either.

GameSpot (http://www.gamespot.com/pc/rpg/finalfantasy7/news.html?sid=6212668) summarizes everything known about it
GamingUnion (http://www.gamingunion.net/news/square-enix-countdown-hinting-at-new-saga-game--203.html) thinks it's a new SaGa game
Kotaku (http://kotaku.com/5302794/hey-look-its-some-square-enix-countdown-clock) thinks it's a new FF game called "Four Warriors of Light"