MTHaslett said:
...
There is no need to have Maul get torn apart in episode I and then torn apart again in episode II. He is simply being rebuilt into Grevious somewhere in the background o episode II until he is somehow revealed.
...
This is something I am trying to wrap my head around as well. If we have any indication of Maul in Episode 2, he should be fully formed as grevious. The 10 year gap between Episodes 1 and 2 is too long for him to be floating in a bacta tank.