http://www.gogaminggiant.com/2010/10/22/fallout-new-vegas-hardcoe-mode-special-reward-revealed/
Apparently the special reward is the achievment itself. Have achievments reached such a level in our gaming society that we consider them a "special reward" in and of themselves?
I remember back in the day when you played a video game uphill both ways in the snow with a notepad and pencil while angry wolves were chasing you and the only "achievment marker" you got was a pile of empty Mountain Dew cans beside your desk... umm... I forgot where I was going with that... Shouldn't I be in bed?