My thoughts on Google IO
I've seen this rated as kind of a mixed bag, but I really like it so far with the exception of a few missing features. This was rumored to be the big unifier in chat, so let's see how well it does this.
Let's start with looks. The apps all look beautiful. The Android app has a UI that is consistent with the Chrome app as well as the apps embedded in Google+ (and assuming soon to be embedded in Gmail). The indicators are clever for showing where in the conversation your friend is as well. The little heads are easy to understand and informative.
Now the syncing. Now when I get a message on my computer and read it on my phone in Hangouts, the status is synced. This works beautifully and seamlessly. The only major problem is there is no tablet support. Well, that's not true. It supports the iPad. Just not Android tablets (yet)... What's up with that?
Now I have a convenient way to chat with video, text and picture on (just about) any platform. Hangouts was even able to pick up my incoming Google Voice calls. Another plus.
There are a few things though that are difficult to get at first. If you used Google Talk you probably know that there is the concept of "Status" messages. You can go away, idle or active. Those are gone. (Not entirely, but I'll get to that).
The status is now much simpler. Google Hangout is real time chat but closer to SMS/BBM than what we commonly think of as IM. When you send a message to someone, it doesn't matter if they are "offline" or "away". They get the message on whatever device they look at first and they get it when they get it. Much like SMS. The benefit though is that you can see when they have the app open and you can see when they read your message. This is indicated by looking at the profile icon for the person you are chatting with. Greyish means the app is closed and full color means they have it open.
Now, there still exists some form of "I'm at my computer and can chat." That's indicated by the Green bar under an icons head in your "Buddy List" and at the top of the chat window under their name. I believe it's just visible on a computer as all phone messaging is treated as pseudo realtime as described earlier. What this indicator does is lets your friends know you're there. Just like you used to do in Google Talk.
This brings me to the next feature I like. What if you don't want to be messaged? You can snooze notifications! I really love that there are timed snooze periods. It makes it super convenient to just snooze chat for an hour while you finish something up and then be told what you missed. When you snooze, it actually snoozes all your devices too! So your phone will stop buzzing too. When you are snoozed, the green bar also disappears on your friend's clients. This lets them know you aren't immediately available anymore.
Now the last thing that I've heard some criticism about. "This doesn't integrate SMS!" and "What about Google Voice". I've been a Google Voice user for a while now and I use Google Voice SMS a lot, but... I have to say I don't care that Google Voice SMS is not integrated for one big reason: This replaces SMS.
It's not meant to integrate SMS, but rather offer a total replacement. In fact, if you message a phone number without Google Hangouts, it will offer to SMS them a link to download it, which I find pretty cool. I'd much rather all my Gmail using friends message me in Hangout than SMS anyway. That way I get read receipts, pictures, video all integrated.
So finally... what is Hangouts missing? Besides Android Tablet support (still baffles me).
First, status messages. I already talked about the actual status, but it'd be nice to display the user's latest G+ status next to their name or in a hover over in the Hangouts list. It's a small thing and not a big deal.
The next is Voice calling. Now, I can receive incoming Google Voice calls just fine in Hangouts provided I'm on my computer, but I can't do so on my phone. I also can't initiate a Voice call from the computer. It only provides a Video call button. I haven't tried it yet, but I'm assuming it's like Hangouts before where I can turn off video, but it would be great to have a "Voice Call" button.
Overall, I think that Google had two goals. First, to unify their Google Talk platform with Google Plus and Google Plus Messenger. This was undoubtedly accomplished. The second was to replace SMS. SMS is ancient technology and one that is less and less necessary. People still cling to it because it's compatible with every phone on the market. Well, now Hangouts is on any smartphone. So it doesn't totally replace it but it could replace it for a number of people. I love using it so I'll do my best to get my friends on board so I can enjoy the convenience of unified messaging.
Might be a part 2 later on other aspects of IO, but haven't decided.