Except Halo ODST played much better than Halo 3 did. I don't see a step forward as a milking. When a game surpasses a prior installment in almost every way, it's definitely not milking it.
As for the "anime" (which it can't even be called that, since it's a collection of short stories by different animators); it's fanservice. Remember when they made the Super Mario Bros Super Sunday Show? Was that milking the Mario series?
And to the movie- that was long abandoned like 2 or 3 years ago. I seem to remember a Mario movie that came out too............ but nobody complained of that being milked.
It's not really right or fair to say a series is being milked when they're simply making new installments for their franchise. If someone can honestly say this is milked, they need to take a hard look at something like Zelda, which has had several games tailored to specific demographics, comics, "Sound and Drama" cds, a television series, several promotional games, etc. Mario, Zelda, Madden, Need for Speed, and plenty of other games are far worse than this, and only a couple of those should even be considered "milked".