Ok, maybe not, but one company has taken a bomb defusing robot and fitted it with weapons for use as a remote controlled soldier.
Army Prepares 'Robo-Soldier' for IraqThis might be good for sneaking up on an enemy that hasn't seen it yet, but it doesn't seem like it would be all that effective once spotted. At a top speed of 4MPH it's unlikely it could evade a rocket and it seems like it would be fairly easy to circle around behind it and either snap off the antenna or tip it over.
They need to build a bigger version with a faster engine, armor plating to make it into a mini-tank and enough room to carry a couple of chainguns and several thousand rounds of ammo, plus a rocket launcher.