We can see this with a game called "Spell of Genesis" it has an external "wallet" called "Book of Orbs" which also intertwines several other games with blockchain-based assets, you can then view, trade & store indefinitely all of your assets there. However this is an independent company, focusing mainly on their products, I'm sure an open-sourced "VLC-codec equivalent" app incorporating a vast amount of crypto-assets in a unique and user-friendly display will blow the masses and become an infamous pocket essential. Until then it will be a shitstorm of Eth smart-contracts trading within independent labels and their own game assets...

Quite sad imo really, one day a game will be willing to pioneer a multi-game asset and allow it to be used universally in whatever application the owner sees fit. Then we will see all the larger establishments incorporate the idea as a custom feature, I envision Magic: The Gathering, Blizzard and the likes to be those whom are hesitant at the start, yet will be the ones who are most profitable and whose assets will undoubtedly boom in value. We will see items moving across games and perhaps being used in future championships of eSports. There may be a sword, crafted to unique specs, which had a chance roll of 1 in 999,999,999 of being created, which nobody else has ever been able to craft since, yet it has been passed through the years from merchants to users, but with smart contracts, essentially the owner may "lend" the asset to the official company, which would allow them to use the renown asset.

But really gamers, could you imagine playing with Pokemon cards in World of Warcraft? Let's get up on it!

For more hypotheticals & general dev brainstorming, see this video;