I'm excited about all the Google Assistant stuff. Google Home is not something I'd personally need at this point, but I think it has more potential than something like Echo (except for shopping, probably).
Allo is something I'd totally use, but I don't really understand why they are keeping Hangouts alive. Sure, it could be an enterprise tool, but so far it's not clear to me if Allo could be a full replacement. My guess is that it will be Android/iOS only for some reason, but I'm hoping they will take the Telegram approach and make it available everywhere.
The bot-chat part of Allo also is a really interesting extension of Google voice search. AI is what's finally going to make our smartphones smart.
From a much larger perspective, bots and voice recognition mean that we no longer have to adapt to the computer, but the computer adapts to us, to our natural language. It took a while, but we are finally there.
I've been running the Android N preview from day one, but there were some pleasant surprises. But the seamless upgrades are a huge deal. I'm glad they looked at Chrome OS and brought that over to Android.
Speaking of Chrome OS, Android apps on Chromebooks are a huge, huge deal. The addition of the Play Store will make Chrome OS a realistic Windows replacement for even more people. Maybe I missed it, but not talking about this in the keynote is so weird.
The announcement of Android Instant Apps got me really excited. There are so many use cases for this. If it will eventually be as seamless as they promise, I think it's going to be a much used feature.
What excites me about Daydream (apart from the fact that such a nice name isn't no longer attached to a screensaver) is that it shows a realistic future of VR, where all you need is your phone, a headset and maybe some controllers. Phones are amazingly powerful and with 4K displays and Unity and Unreal support, Daydream could mean great VR for a mass audience at a reasonable price.
I could keep my eyes open, but I wasn't really focused when they talked about Android Wear 2.0. There is literally nothing that excites me about wearables at this point. I don't even want to write about it.