Prominent Dota 2 patch analyzer Matt "CyborgMatt" Bailey was gifted a flight in for this weekend's The International tournament, along with a Valve HQ tour to boot. During his roundabout he was shows some interesting things that might get Dota 2 fans hearts' all aflutter. A myriad of items were being organized for what looks to be a Dota 2 merchandise shop at The International. Some of the items available include trading cards, plush and inflatable couriers, and a display action figure (to be made available summer 2013).
The trading cards are shown to be part of a special deal for merch purchasers. A sign reads, "Spend $40 to get a pack of cards. *Guaranteed to contain 1 courier." The sign then has images of three "international" couriers that, I assume, are only acquirable through Valve's trading card game -- each of which is likely usable in-game. If couriers are your thing, the Zonkey (Zebra/Donkey) will come with the inflatable or plush Donkey courier.
Axe, in action figure form, was also available to check out (though not available to touch). His stand reads, "Prototype Shown Coming Summer 2013." CyborgMatt also has a picture of a smaller Nature's Prophet non-moving figure, though if that's related to the Valve merchandise of simply a toy from a friend -- who knows.
Valve's The International Dota 2 tournament starts this weekend, coinciding with PAX Prime. Expect all of the juicy details in a more official manner soon, or check out CyborgMatt's picture feed for a better look right now.