Just a thought:

GS and GSD have incorporated elements of almost all the various different Gundam universes, right? I mean, they have elements of the original Gundam series and its spin-offs, elements of Gundam Wing, and, though loosely, bits of G Gundam (Burning God Finger anyone?). So let's say they continue the process of "Borrowing" from other series and move into GS3- What's left? Does this mean that we'll see...... Gundam Seed Destiny: Superior Defender? O.o?