Its an old advertising truism that "when you have nothing good to say about your product, at least say something bad about your competitor's".
The obvious corollary is that when your competitor spends all his time trashing your product, you should take them head on. Microsoft's only mistake with the laptop hunters is that it took three freaking years worth of product libel to get them to respond.
Hopefully they'll respond a lot quicker this time, because of course, the fruity attacks *will* continue.
(Along those lines; I'm curious to see what the Cupertino response will be to the Moto-droid iDon't campaign. I suspect loud legal action.
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