Mojang is preparing to release Minecraft 1.7.3 next week, which brings Twitch TV integration to the game.
Minecraft 1.7.3 is not as big as the last update (1.7.2: The Update That Changed The World). It's mostly bug fixes, as well as the Twitch TV feature, which will allow you to easily broadcast your Minecraft games. Other changes are a new Mojang logo on launch, new 'Notch' shader added to 'super secret settings' and better fullscreen support on Mac.
If you own Minecraft and can't wait for the official release, you can try out the pre-release 'snapshot', which has all the new features and bug fixes. Download the current Minecraft snapshot from Mojang. The game launcher allows you to switch between the current version and snapshop when you've downloaded it.