Fishing has been down for more than a week now. They are working the bugs out of it, I believe. Just think of it as... the water is frozen... so um... yeah... no fishing.
Of course it will return! The admins didn't work on it for several months only to give up on it. They've just been focused on the X-mas event recently, it'll probably be back up after the New Year.
But seriously, I'm certain that now that the events are over and the mistlertoe thing is running smoothly, the admins will have more time to work on these kinds of things. Just be patient.