In the month of May so almost 6 months ago, there was Four Loko (represent) spilled. But up until now there have been no problems.
Sometimes (at least, I've had it happen) you can have a spill, especially with something sweet that doesn't cause any problems electronically, but eventually the residue from it starts to cause trouble mechanically (and even if something sticky like soda doesn't immediately gunk up switches/action, it can gather dust and such in a combined mess that does over time). Usually what I do is take everything apart and clean all of it (other than the controller of course, and being careful with anything that might rust or need to be oiled afterwards) and then make sure it's *completely* dry before reassembling.
I don't know if there's an easy way to (safely) clean a laptop keyboard
well without taking it out of the laptop, I've only ever cleaned desktop keyboards before, hopefully someone else has some advice on that. You *could* try popping off all of the problem keys and cleaning the key caps in some soapy water, then taking a
damp (not wet, even if the keyboard's base is sealed I wouldn't want to risk anything dripping into the laptop) cloth and wiping all of the surfaces the keys make contact with, and the plastic scissors.
If the sticking is caused by something that got under the rubber membrane, though, you'll need to take it entirely apart, I think. It might be just as easy to replace the entire thing, if you have a model that has cheap replacements (I know I've seen some for ~$10)