Just like the last time, I got some info on Babel.

• 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

Just got to play with it for less than a minute. Will update if I get to play with it for longer.

Updates:

• SMS/MMS sync is not there on the app that's being dogfooded
• And it's gonna be hangouts not hangout
• I already mentioned this in the comments, Google Now will get location based reminders. Example: "Remind me to call Lisa when I get home"
• Gmail is getting a UI overhaul, it will be "Holofied". Swipe from the left will give you access to your inbox, drafts, labels, etc much needed improvement in my opinion.

I may not be able to get much info about 4.3, my sources are not taking part in the internal beta program. May get hardware info if any next Friday or Saturday.