Hmmm, given that a DVD drive is required, I would assume that it means that the game would not fit onto two CDs. Since XC2 had all of the game data on one disk (the other disk being for high-qality background music that defaults to midi if you choose not to use it), that implies that either 1: XC3 will have GREATLY more scenes in it (like twice as much as XC2) or 2: XC3 will contain animation in the main game (most likely either in the form of animated cut scenes, or some form of full-animation).
Now, to comment on Takuya changing sexes all the time, here is an idea that I had when I first saw the scene in XC2 where Chisato tries to duplicate the explosion and transform Kouji into a girl but fails. My thought is that the original drug (or the reversal of it) in XC1 left Takuya’s gender unstable somehow, which results in him later being turned female by things that would not have the same effect on regular people.
As for my hopes for the game, I would like to see a couple of happy endings that have Takuya permanantly female. In XC2 the two endings with Takuya and Kouji were semi-happy ones, the female Takuya + Maiko ending was sort of unhappy (being forced into a lesbian relationship for an indefinite period before Maiko would surrender the antidote), and the other female Takuya endings were definitely unhappy ones. Let’s see Takuya actually happy as a girl for a change.