well, its not designed to, if you can sync a blackberry through isync or outlook then that info will inturn be synced to mobile me but no direct syncing to 'the cloud'.
I think Apple needs to think more about how this is all supposed to work when multiple people are involved. For example, my wife has a BlackBerry, I have an iPhone. Is MobileMe any good for us? Probably not.
They don't even really talk much about how this works when multiple people are involved. For example, can multiple family members all enter events on the same calendar? Can a family have a shared address book that gets pushed to everyone? Photos? If I've subscribed to another family member's calendar, are their entries automatically pushed to my iPhone when they make changes, or only when my desktop iCal app manages to update itself? What about small businesses?
The odd thing is, that MS Exchange was really designed as a collaborative tool, not as something to be used in isolation. Apple has taken it and turned it into a personal sync tool.
I would rather my iPhone be able to sync via Bluetooth, the way most other smart-phones can, than pay $100 a year to sync over the internet. Am I alone in this?