The coming messaging service from Google called Babel will be much better than Apple's iMessage, and the reason is that it will be available for all different devices. Both as native apps in all the different app stores, and as a web service and even a Chrome app.
One thing that I missed a lot when I switched from iPhone to an android phone, was iMessage. My whole family uses iPhone and iMessage. So after switching it was not so easy to send messages to them, and they love using iMessage because they can send messages and large photos and files totally for free to each other.
So if Google Babel will be as good or better, then maybe I can convince them to start using it so that we all can message each other easily again.
And no, I will not try all the other services you probably will recommend now. If it is one service that I will try to make them use, it will be Babel.
Update: A credible The Verge Forum member says:
- Babel will be called Hangout
- The icon will be similar to the messenger icon, except that it will be green
- UI will be Holo (obviously), a swipe from the right will give you a list of conversations
- Unifies messaging as expected