Assuming the forecasters are correct (8-14 inches of snow), and given my past experiences in these situations, I would say that the only flights that stand a reasonable chance of moving are the internationals. CO seems to be quite loathe in cancelling these flights.

But as for domestics, they tend to prioritize flights heading to other hub cities (IAH, CLE), probably in the hopes that the other hubs can accomodate at least some of the affected pax. But again, this is only based upon my experiences over the last two years with CO at EWR, so take my info. at face value.