Dude, it just happened. They are probably scrambling to fix it. Those mining now will be rewarded nicely if they can fix this.
Yea, no immediate fix will be available if they need to patch it. They'll need to give people time to update wallets so nobody forks down the wrong path. This will be good for us miners for a bit.
We're working on it/analyzing it now. It is going back up now quickly but the transition seems to have made it drop to nothing for a few minutes.
It's been pretty erratic so far. going as low as 1 then going back to 4 and dropping to 1 again..
EDIT; It does seem to be on a steady rise now, those first 40 blocks have been nice to me
