Valve apparently invited a few YouTubers up to its offices last week to talk about the future of Steam, as a few (including John "TotalBiscuit" Bain and Jim Sterling) have now published videos running down what they talked about and how Valve is thinking about dealing with Steam's discoverability problem.
Both of the afore-mentioned videos are worth watching in full if you're curious about the future of Steam; one of the most notable takeaways for devs is that Valve is thinking about how to revise Steam's game sorting algorithms to bury/block "fake games" (the phrase Valve staff reportedly used to refer to games built around asset flips, etc.) with minimal impact to game developers at large.
While this is second-hand information, a Valve representative confirmed to Gamasutra that these conversations did happen -- and it lines up with Valve's previously-stated plan to replace Steam Greenlight with a fee-based game submission system, Steam Direct, later this year. One of the chief reasons the YouTubers were reportedly involved is that Valve is planning to revise its Steam Curator system (which many game-focused YouTubers participate in) and add a complementary system, Steam Explorers.
The idea is that the Steam Explorers program will be open to anyone and ask participants to play games that aren't performing well on the platform. Explorers will then be able to vouch for a game as being "good" or of value (it's not at all clear how that would be defined or policed), which will in turn raise that game's standing in Steam's algorithmically-powered eyes.
Valve is also reportedly mulling over how to better incentivize Steam Curators (including, potentially, some form of compensation) and is thinking about adding in useful tools like a game key transmission system -- which devs could presumably use to send copies of games directly to Curators, addressing the problem of key resellers scamming devs out of keys by pretending to be notable players in the industry.
For more on what Valve staff discussed and showed to the YouTubers (which was all very clearly in the "mock-up" stage, with no planned roll-out schedule), check out the aforementioned videos.