We just had a generic email from Travelbag (owned by Emirates, i believe) - not that we have a booking (sadly) - that check-in has been closed for anyone preparing to travel to or via Dubai until midnight tonight. Presumably, this is to give them some headroom to manage the number of people stuck at the other end.
One might argue that the trouble with hubs, and an airline that is immensely popular operating basically full flights to and from said hub, is that when something big goes wrong its incredibly difficult to sort it out without closing everything down and starting again.