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ValveTime.co.uk | Valve News, Forums, Steam
There was a developer walkthrough over at GDC in San Fransisco and someone over at GameTrailers seemed to have recorded it, I thought it was pretty interesting, so why not share it to those who've missed it. And I hope I wasn't the only one. I looked around over the forums a bit, but I couldn't find any thread about this. Sorry if one already exists.