9. The Oracle Problem Is Cleverly Resolved
It was extremely unfortunate timing that the original Oracle actress, Gloria Foster, passed away during filming for the two Matrix sequels, and so for Revolutions she ended up being replaced with Tony award-winner Mary Alice.
Thankfully not only did Alice do a fantastic job taking over the role from Foster, but due to the nature of the Matrix, the Wachowskis didn't have to work too hard to make the change in appearance convincing.
In the movie, the Oracle says that she made a choice which cost her her original appearance, and the Enter the Matrix video game further reveals that she allowed Ramachandra to trade her "shell" (her original facade) to The Merovinginian in order to keep his daughter, Sati, safe.
The Merovingian believed this would destroy the Oracle, but because it was only her armour-like shell, her "real" appearance survived underneath. While it's perhaps not ideal that the finer details were given away in a video game, the movie really didn't need to get bogged down in the minutia of the casting change, and this was basically the smoothest way to do it. Bravo.