"Double stakes" applied to Go could be: The same/similar to backgammon, if the games are played for money or if they are played for some sort of online fun/honor betting points. Or it could just be increasing the amount of rating points at stake (we know from some other threads that many players are very protective of their rating points!
The most obvious problem is that the correct doubling point is 75% winning chance, so if you double with ~76% winning chance, the opponent should resign. I feel for a game like Go this is too low, correct strategy would lead to doubling out the opponent too early. So the doubling cube could be modified to instead be offering to give 6:2 odds or something (person offers to pay 6X if he loses, or take 2X if he wins -- this raises the drop point to 87.5%). Or if you wanted to use this device purely as a way to get a stubborn opponent to resign a game that is clearly lost, you could make the odds even more steep.
Well I don't foresee this idea being taken up by many places, certainly not KGS, but it just seemed like a fun idea to think of.