From RAP in the densitometer thread:
"BTW, ordered more old emulsion TRI-X 4x5 on Tuesday from Calumet. They said they had about 100 boxes left."

I received the latest issue of Camera Arts yesterday. In his article on Kodak B&W films (very short!), Steve Simmons says kodak has not yet moved its Tri-x sheet film manufacture to the new plant. "Old" Tri-x sheet may be all that's available even after Calumet reorders. Just a caution that you shouldn't hold off buying Tri-x sheet film waiting for the immanent arrival of "new" tri-x.
Tom