Originally Posted by lol101 
Well, I guess buying old FF lenses to use them on current APS-C DSLR is OK, as long as you don't need wide angle or affordable f2.8 zooms...
As for just needing to refresh the designs, that's one thing, but then you have to re-build the complete industrial production facilities, and that's another matter.
As for wasting money buying non-FF lenses... my definition of wasting money is to "invest" in FF lenses because they "might" work on an "hypothetical" FF camera still to be defined in an unforeseenable future instead of buying lenses for available cameras and take real pictures with them.
When it comes to gear, my approach is to buy what's available, within my budget, and suits my needs. All these ramblings about FF cameras are nice but it seems silly to just keep waiting for the Arlésienne to come instead of using what's already here. As for FF being the "best" format, it's about as exact as saying that 24x36 was the best format in film days...
An other option is to go FF right now and fork out the €6000-12000 needed for a complete FF system from Canon or Nikon... thanks but ... no thanks!
Well, in any case, people have reported that the DA* lenses at least can cover the 135 format in full. That's two currently available lenses for a possible shift to FF. I'm guessing Pentax keeps the upcoming future lenses to also be able to cover the 135 format, just in case.