iMessage on the iPhone has been fantastic and truly changed the way I communicate with my friends and coworkers. From group messaging, to high quality image/video messaging, the delivered/read receipts, it really has become a tool that I use a lot. That being said, I think Apple is making a mistake by only integrating iMessage into their desktop Messages client instead of putting it in the cloud as part of iCloud. By only focusing on the desktop, Apple is prevent a large portion of their users from using the service from their computers. At work like many others, I'm forced to use a PC which right off the bat means I can't communicate via iMessage unless I use my phone or iPad. Same if I'm using a computer that isn't mine. Apple had a great opportunity to make iMessage the first true mobile/desktop/cloud messaging client so I'm a little disappointed they're not taking advantage.