The MBA superdrive won't work on any other computer unless you do a hack to it.
You could always find a broken G4 mini for the case and install a DVD/BD drive in it and you could even mount a 3.5" HDD in the case too for extra storage and sit your Intel Mini up on top/bottom of it.
That's good to know, you are right as it is listed there in the Mini Server accessories. Strange that it only lists the MBA as the only device it's compatible with on the list. It should note that it's also only compatible with the Mini Server too. Don't know why they would limit it to just 2 specific Macs now and not for all of them?