Yesterday's iOS Pages update added the ability to track changes. Jeff Richardson wrote it up and does his usual thorough job of covering iOS features particularly relevant to attorneys. Tracking changes is a doozy.
I've stated several times how I felt that change tracking was the holy grail of iOS wordprocessing for lawyers. I've been playing with it now for a few hours and I agree with mostly everything Jeff says. I do think the lack of comment support will be a dealbreaker for some and completely irrelevant to others. The good news is now there's a variety of options on the iPad for change tracking. If Microsoft doesn't hurry up and get Microsoft Office out for iOS, pretty soon nobody's going to care.