It seems that Digikey is out and several other suppliers have low numbers. No problems on the other packages. What's up?
I don't know if that is the present case but there had been pretty bad shortages on 328P chips some years back.
Digikey is out, more due 8 Jan.
Mouser is out too. More due in: 9,782 1/13/2014
Still available at Newark: 5,821 in stock for same day shipping
Avnet has them still. 614 Stock