Apple's new iMessage sends messages between accounts associated designated e-mail addresses (as well as certain phone numbers). Apple's iChat also sends messages between accounts associated designated e-mail addresses. For the most part, for example if one uses the default iCloud settings, these e-mail addresses are the same. Yet, as near as I can tell, iMessages only work between iOS devices and iChats only work between OS X machines (or machines running specific chat clients).
If this is correct, is there a way to get around this limitation using an iMessage client for OS X, or is it possible to configure iChat as an iMessage client?