Coke == dead
Water == salvageable
The sugar in the coke will
1. Corrode the connections inside the laptop
2. Will tie together the connections (cause it's a conductor) and short the laptop.
Water is a different matter, it's conductive, but not corrosive (quickly anyway), so if you have the laptop off when you spill water on it, you can dry it out and have a chance to save it. So as it stands I'd say you're SOL with your laptop ever working again. (best thing you can try if you REALLY felt attached to the laptop would be to replace the keyboard, touchpad, and everything else the coke touched)
P.s. if you really wanna try and save it take it all apart, and put the motherboard in a bowl of distilled water for about 20 minutes, then bake at lowest temp possible until dry. The water will get into the nooks and crannies of the board and might clean out the coke, baking it will fully remove all the water and hopefully will slow/stop the rust process. (mind you this is a last ditch effort)