If these games were to be released in north America, this is how I see it happening:
Xenoblade: Spring of 2012
Last Story: Summer of 2012
Pandora's Tower: Fall of 2012
The release for both Pandora's Tower and Last Story could be switched, so I assume either one could be released in the other's time slot.
As for Dragon Quest X, I see the samething happening to that game as what happened with Twilight Princess. The Wii version will get released earlly in november of 2012 and the Wii U version will be released alongside the Wii U itaself sometime in november or december of next year. So, by the end of 2012 we should have anew home console and the success of Operation Rainfall.
OK, first off of the 3 Rainfall games, Pandora's Tower is
by far the least likely to reach NA. I'd be very pleasantly surprised if it did. It wasn't developed by a Nintendo studio like Xenoblade, and it wasn't helmed by the creator of Final Fantasy like Last Story. Aside from being an interesting experiment, there's just nothing going for it that would especially draw NoA's attention right now.
Next, you forget that the Wii version of Twilight Princess launched
before the GameCube version did. The Wii version released in November alongside the Wii, and the GameCube version released a month later in December. So if you want your analogy to hold true, DQ X would release on the Wii U in late November, with the Wii version (if it even releases in NA, which I highly
doubt) releasing just before Christmas in December.