Anybody who owns or will own a Dota 2 Compendium will gain instant access to the new content that was added to Dota 2 tonight. Valve is calling this the Overflowing Compendium update and includes new styles for the Squawkins courier, the Mini-Pudge courier, chat emoticons, weather effects, and a "live rewind" feature for spectators.
WEATHER EFFECTSWHAT IS LIVE REWIND?SQUAWKINS STYLESMINI-PUDGE COURIER
With this update, if you own or purchase a Compendium, you will receive your very own Pudgling, a cute yet still-revolting Mini-Pudge Courier. Not disgusting enough for you? If your Compendium reaches Level 50 then you'll also get his extra smelly alternate style. This upgraded version will also come with a classy golden hook.

CHAT EMOTICONS
Mere words cannot convey the true depth and breadth of your emotional response to the game of Dota. For that you need Dota-themed chat emoticons! And you need them to animate! These new emoticons work in-game and also in the dashboard chat rooms. Owning the Compendium gives you access to all 25 emoticons forever.

Now, the update originally came out and locked those weather effects behind various Compendium level gates. That is, if you wanted the rain weather effect, you either had to grind your Compendium to level 120 or pay your way there. Valve listened to the upset fans and removed those requirements a very short time following the release.

Thanks to sales of the Compendium, the prize pool for The International is sitting at a staggering $10.1 million (USD). Dota 2's The International has already surpassed the top prize pools for many professional sporting events from around the world and it still has room to grow before it kicks off on July 18.