You see, in order to use the iCloud features that are available today, it is required that your iDevice runs iOS 4.3.3 or later. Since Verizon's iPhone 4 is still stuck with the older 4.2.8 version, there will be no way of using the cloud services on it, or at least not until an update comes along.
The list of currently supported devices includes:
- iPhone 3GS
- AT&T's iPhone 4
- 3-rd and 4-th generations of the iPod touch
- any iPad or iPad 2 model
As we already mentioned, all of the devices need to have their firmware updated to version 4.3.3. Besides that, all of the currently available iCloud features can be also used with a Mac or a PC running iTunes 10.3 or higher.
We are guessing that a software update for Verizon iPhones is already in the works, but when it will come remains a mystery for now. Nevertheless, it should not take too long so keep an eye on iTunes for update notifications.
source: Apple via MacRumors