I agree with the feeling that one Quantum ship will be based in Asia. Asia has been gaining lots of momentum in cruising and with preferences shifting to european and american cruise lines over the traditional asian cruise lines, it will be no surprise if a Quantum ship is based in this region.
An Oasis-class could be out of the question in my opinion. It's far too huge for it to be effectively filled for Asian voyages. But it will definitely be awesome if one of those 225,000 beauties could come to Asia! :D