Osram Sylvania has announced that they are discontinuing the manufacture of large PAR lamps (i.e. PAR46, PAR56 and PAR64). They have also announced a voluntary recall of all large PAR lamps manufactured since November 2016.
According to Mark DeLorenzo, Entertainment Business Unit Manager at Osram, previous to November 2016 all large PARS were made in the USA, but that factory is closed and the equipment no longer exists. Their only manufacturing facility for these lamps is in China, and they have had such terrible quality control issues that they don't see an alternative but to cease manufacturing.
GE is no longer making these lamps, either. I don't see them on the Philips web site, although I do see off brands available at some online retailers but a quick search finds no 1000W PAR64s. So, we're coming up on the end of an era. The inexpensive and sturdy PAR is being replaced by much more expensive things like the Source4 PAR and various LED units.