Where the heck is Microsoft? Earlier this year, Microsoft launched the newest version of Windows Mobile (version 6) and there’s a slew of devices built on the new mobile OS (we have video of them here) with more coming (like the new HTC touchscreen handset).
The blogosphere may be a constant and unabating stream of news, but to the larger public news comes in cycles. Apple is winning this cycle, but frankly that's ok. Horning in on this cycle would not only be difficult, it would probably be counterproductive. In a fight against an unreleased product, all you can do is speculate about how your product is different/better/etc. That sort of speculation would just be begging people to revisit it later to crow about how you were wrong. Much better to wait and see.
If I were Microsoft, I'd be ready for the post-iPhone cycle - the one where you get tally off the "Cons" of the iPhone and mention how many (most? all?) of them are "Pros" for your platform.