The mysterious "Steam Box" will be ready to prototype in the next four months, according to Valve head honcho Gabe Newell.

'You need to actually be able to directly measure how aroused the player is.' - Gabe Newell.

"We're working with partners trying to nail down how fast we can make it," Newell told the BBC ahead of this evening's BAFTA awards. "We'll be giving out some prototypes to customers to gauge their reactions, I guess, in the next three to four months."

It's unclear if "customers" means actual consumers, developers, or publishers. We've followed up with Valve to clarify this statement and are awaiting reply.

Newell clarified that most of the preliminary work on the console was done, but it still had to fine-tune some technical details. "There are noise issues and heat issues and being able to [deal with] that while still offering a powerful enough gaming experience is the challenge in building it."

The big issue that the company is stilling mulling over is the controller. Valve is considering adding sensors to determine the player's body state, so it could potentially develop software to adapt to that.

Talking about horror series Left 4 Dead, Newell said, "you need to actually be able to directly measure how aroused the player is - what their heart rate is, things like that - in order to offer them a new experience each time they play." This would certainly open up potentially fascinating feedback loops between games and their players.

Unfortunately, Newell was unable to discuss the upcoming console's price, nor whether Half-Life 3 or Episode 3 is in development. No surprises there.