I just showed this to a friend of mine who's a big CreepyPasta guy and is active on a few of the sites where CreepyPasta enthusiasts congregate (except for the CreepyPasta Wiki, which, in his words, is "run by a bunch of self-righteous, elitist hacks who don't get that they're supposed to be a wiki and not some high-brow writer's club that wants to forget the stories that made CreepyPasta big in the first place. Seriously, fuck those guys."), and he thought it was awesome.
His only comment was that having Slender: The Arrival on Xbox 360/PS3 kinda removes some of the creepy ambiance that adds to the game's scare factor (hard to have headphones plugged and still playing something like this comfortably in front of a TV screen.
Personally, I kind of agree with him, but it's still awesome promo material.