A few details are emerging from people who have read the latest issue of Famitsu (which is yet to be released officially) including a good explanation of the background story in Final Fantasy XIII. Motomu Toriyama, the games director also comments on the year ahead and the possibility of a playable demo sometime this year.

The blue sphere seen in previous scans has been confirmed to be the floating city Cocoon. Cocoon was built by a superhuman entity called Farushi/Falsh (ファルシ) to protect people from the threats of Pulse. People chosen by Farushi/Falsh to carry out some kind of mission are called Rushi/Luci (ルシ). Both the Blond haired man and Pigtailed girl are Rushi/Luci. Summons come to the aid of the Rushi/Luci and appear in "digital form". The entity that built Cocoon is not the Crystal.

Toriyama says that the games theme is "determination" and that he'd like to give players the chance to play a demo of the game in 2008. It's unsure whether he means a demo at a games convention or a public release.

Thanks BlankChocobo for the translations so far!

Source FF&KH Blog