It won't carb if you take it off of the gas. The gas would be absorbed, but then there'd be no more gas coming in to keep it carbing up.
Why don't you prime the keg, if you're keeping it at room temperature anyway? I've done that. Just 2.5 ounces of priming sugar dissolved in 1/2 cup water boiled for a minute, put into the keg, and then the beer racked into it. Give it a shot of co2 to make sure the lid is seated (check for leaks!) and then let it sit at room temperature until you have a place in the kegerator.