This situation is temporary, since you'll be getting a replacement right away, I presume. Before you rush out, check with your filter documentation (if you still have it).
Ours has conked out before during power failures, but we've always been able to reset the motor somehow. As much as I hate to admit it, I forget how we did that---my wife took care of it! Haha.
Don't worry about a water change just yet. The most immediate threat to the health of your fish is the dwindling oxygen levels that will take place now that the surface agitation caused by the filter has been removed.
They should be fine for a few hours while you get this filter business fixed. If it's gonna take longer than that, you'll need to put a bubbler/airstone in there.
Good luck.
Big Vine