Don't bet on it. Thanks to loose lips from our good friends, the South Koreans, the North has been able to minimize their visible preparations to an amount of time that is probably without equal. Mobilization requires certain tasks to be performed, especially in a large combined arms assault, but they've frontloaded most of it.
And yes, while we do watch, the North Koreans will periodically mobilize in a way that indistinguishable from an attack, save the firing. Sometimes clumsy, sometimes very subtle, just to keep us off guard. I'm sure they hope that crying wolf long enough will deafen the right ears. As far as the South Koreans are concerned, I'd have to say they are right.