considering notch himself hasn't killed one yet(i don't know if that is till true though) i would say diamonds or this
"Look down now back up.The ghast is now diamonds.I'm on a horse."
XD old spice
but no they shouldntdrop that they should drop something awsome
i think peopel have become to attached to diamonds i am startign to drow sick of them
they should drop web or something/???? unknown use but imagine it sounds awsome
Some magical floating/fire material is its a flying material make it into a 3x3 square on a crafting table for a flying device if its a fire material it will most likely be used for flaming arrows >:biggrin.gif:
How about fire blocks? There was a plan to use fire blocks for making chainmail armor, and the armor is still in the game so this could be Notch's way of re-adding it. It would be pretty cool thing to have, and be still used as a projectile. This would give a good reward and reason for killing gasts.