+3GB on the GTX380..
The demo does do some impressive things.
Their prebaked lighting looks very nice.
A lot of information about the tech demo. (google translate version of the OP)
Some papers and videos on Squares baking ray-tracers etc.
Cool, I did not realize Square had something like this.
Ubisoft and Crytek have something similar. Not sure of other companies though.
I think Agni's philosophy would be possible 720p @ 60 fps on next gen hardware. Just look how far Xbox 360 and PS3 games have come over the years. However, from the translated Japanese page, they said that they had something like 1000 textures per frame. To max out all the detail must have taken considerable art time as well.