And the memory and resources load for all that is.....?

Let's keep in mind that we already have some experience with graphics goodness that is purely for eyecandy purposes, and not really any  practical output application,

It's called 'Windows Vista'.

And according to the article, this was all -single bounce GI- only one permitted reflection in the process. True GI and radiosity would involve numerous raybounces.....and each additional set of bounce returns would up the processing load either logarythmically or geometrically....not linearly. So they are going to have to clamp it at some low bounce trace number to keep the data from exploding to impossible levels.

Then they are also getting into the realm of the granularity of the real world. As in 'how many possible control boxes can you pass in a poorly lighted area and not even catch a glimpse of them'? GI and Radiosity sounds good.....until you consider the fact that unless your switch or door or whatever is flashing in bright colors, or has a sign on it saying 'Next Level, Stupid!' then the closer you get to simulating real world lighting, the closer you get to real world visual issues; one of which being how easily things can blend together in poor lighting conditions.

Current game makers are unfortunately far more concerned with 'pretty face and perky tits', and not building actual =games=. Hopefully they do reach the Holy Grail of GI and Radiosity soon; then all they will have left to fall back on is that 'creativity' thing in designing the game......