It's 2013 and no Android OEM has perfectly and natively supported...
Android on emoji has always been puzzling. Even with the announcement of emoji support on 4.1, emoji input has been disparate and relegated to be handled on an app-to-app basis. With 4.2, there is an improvement, however. On Nexus tablets, I've read that it's natively supported with a stock emoji keyboard in place, but on my Nexus 4 on stock 4.2, it's absent. A flash of the stock emoji keyboard was necessary to make it usable on my Nexus 4. And even with that you need to pull down the notification to switch to the emoji keyboard--1 step more than iOS's implementation.
On the Galaxy S4, it's nowhere to be found; same goes for the 4.1-rocking HTC One and Xperia Z (and ZL). Using 3rd party emoji keyboards end up giving you squares when you leave apps that have emoji codec native to that app (ex: whatsapp, go SMS pro). The idea is to root and flash those stock keyboards. Which bites. Why is this so hard to implement on stock.
Now, we have emojis on the Google Hangout, a much better implementation than the wingdings-ish emojis on stock 4.2, IMO. And I hope they eventually make their way as standard emojis across the OS.