So, there was an indie Steam presentation in The London yesterday for this - basically, instead of repeatedly pestering the 8 men at Valve who have to sift through indie submissions and hope for the best, they're setting up a voting system whereby interesting/ unusual games get voted up and transcend into Steam.
So, at least there's now a transparent process where one simply didn't exist before. This has me very excited, since the worry that someone at Valve might just reject The Swindle and that's it isn't going to happen - I've got a good, strong chance of making enough noise to get it on Steam. And that's a HUGE relief.
It also means brillo things for the likes of Zomboid, Thomas Was Alone, etc. It's not a perfect system, and it'll still need human input, but it's WAY better than the current dark black void of silence.