I called yesterday to order, same thing. He said they've been having 'quite a run on those lately'. They said they expect more in around a week so I backordered them.
If you get a chance, try the 3M Regalite 977's or 963's. (the 963's, I'm told have more ceramic abrasive than the 977's) I've grown to prefer them over the Norton hoggers. They don't seem to last as long as the Nortons (which seem to last forever at a 'dull sharp') but they seem to be sharper longer and run a bit cooler.
My other humble belief about the Regalites vs the Norton hoggers is that the grit break down seems to be a bit more consistant. I always end up with deep gouges after I've pushed the Nortons too far. The Regalites just get dull at an even rate. I suspect this will vary from person to person via pressure used and speed of the grind.
I grab an old norton hogger for the first bevels and to really move some metal quickly, then I switch to the Regalites to carry the initial grinds through.