Discovery is getting increasingly more difficult on Steam as the sheer number of unregulated games piles ever higher. So, in an effort to make finding games more convenient, users can create their own tags that will find their way onto the store listings if enough people agree.
As you'd expect, the trolling has already begun.
In theory, it's a lovely idea. Steam customers can tag games using themes, mechanics, genres or even memes, thus allowing for a new way to discover games that suit your own personal tastes. The scheme will naturally evolve as it goes through the beta process.
In practice, Dark Souls has already been classified as 'Casual,' numerous experimental games are in danger of being branded as 'not a game' or 'hipster bullshit,' and it's just the tip of a tagging iceberg. It's actually rather amusing, but good-natured humorous ribbing aside, it will be interesting to see whether this new system genuinely improves discoverability or ends up drowning games in misleading labels.
Personally we'd like Steam to start cracking down on quality control to ensure that the best software can thrive without being drowned under mediocre crap, but hey, baby steps.