Welcome to the Hotel Cupertino
Consider that iCloud -- if it all works as advertised -- is supposed to allow you to access your music, photos, video, email and appointments across pretty much any device you like, as long as it's an iDevice. Make your next phone a Samsung Electronics Co. Ltd. (Korea: SEC) or grab a BlackBerry PlayBook as your tablet choice and you're not getting any of that sweet automatic update action.
Of course, Apple still supports synching up your iTunes account on a PC with your devices and the iCloud service. I'd bet, however, that Apple might even be expecting a minor iMac bump from those that like to complete the set.
Now, lots of people won't care that they're more locked into an Apple lifestyle than ever with iCloud. But consider how many more areas Apple could potentially extend this service into with applications such as mobile TV and movie streaming looking like the next obvious extensions.
How much of both your work and personal life could eventually end stored in the iCloud? Apple isn't messing around with capacity here; it has already built three data centers to crunch the cloud.
Remember: You can log out but you can never leave!
— Dan Jones, Site Editor, Light Reading Mobile