Japanese magazine Dorimaga took the opportunity to interview popular game and character designer Tetsuya Nomura, who's pretty heavily involved in the upcoming Compilation of Final Fantasy VII and obviously working on the upcoming Kingdom Hearts II.
Regarding Kingdom Hearts II, Nomura indicated that the game is already twice as long as the original and may in fact take up two discs, which is fairly uncommon on the PS2 (Star Ocean 3 being the only Square Enix game thusfar doing it). He also mentioned several obvious additions to the game, such as more Disney characters (coupled with presumably more Final Fantasy characters as well). Sora has also had new motion capturing applied to reflect more mature movement patterns, since he's aged since the first game.
When asked about the Compilation of Final Fantasy VII, Nomura immediately pointed the finger at Yoshinori Kitase (more or less the FFVII brand's father), saying that Kitase had taken the compilation much farther than he had initially expected, as he had only expected to go as far as Advent Children and Before Crisis. However, the compilation project is nearly drawing to a close, and he is confident that it will impact players in ways they hadn't expected. To underline this, he gave Dirge of Cerberus as an example, explaining that although many may expect it to be a run-and-gun shooter akin to the Devil May Cry franchise, people may be surprised as to what genre it actually is. The game will take place beneath the crater Meteor created when it impacted at the end of Final Fantasy VII, and will explore the Turks' background in more detail, presumably suggesting that it somehow connects to Before Crisis. And not only does that seem apparent, but he also mentioned the prevalence of certain characters from Advent Children reappearing in the title, although they would not play an all too major role given that Dirge of Cerberus is Vincent's story, whereas Advent Children is Cloud's.1