Following today’s iCloud mail problems, we are starting to again see reports of iMessage failing to activate on iOS devices and Macs. The service does not appear to be completely down, as I have been able to send and receive a few messages from my phone using my email address as my caller ID, but it does appear that actually activating it is failing for most users. Both my Mac and iPhone are returning errors or stalling while trying to login, while my iPhone no longer gives the option of selecting my phone number to receive messages. Others report not being able to send or receive messages at all (even when using their email addresses as the caller ID on an iPhone).
Some speculate that Apple may be rolling out the unified phone number/email address system that will allow iMessages sent to an iPhone number to be received on a Mac or other iOS device as well. This seems unlikely, since that is a feature of iOS 6 launching in the fall. However, it is possible that Apple is preparing to roll out OS X and iOS betas to support the feature soon.