Yeah, yeah, HAD to talk about it... Though there's technically no point in talking about it. If you haven't heard of it, then either you don't have Internet or you aren't using it for entertainment... in which case you shouldn't be reading Planned All Along in the first place.
Twitch Plays Pokémon is one of the best things to have happened to the franchise since Pokémon Origins! ...Okay, for the fans, anyway. The concept started pretty simple. Put an early Pokémon game on Twitch and then let all users input their own commands. As a result, it used to be quite messy, as some mischievous users would often jump in and derail what had bee done so far, by, say, inputting lots of the wrong command. And causing events such as using the Master Ball on weak Pokémon... Or releasing lots of Pokémon from the PC, just to get the others very angry... But most of the time, it's petty stuff that still annoys a lot of Twitch players, like jumping off the wrong ledge.
Eventually, two modes were created in order to prevent this: Anarchy VS Democracy. As silly as it sounds, both sides were represented by the two Gen 1 fossils. The second mode was created to help get through the harder sections of the game, where devious players would inevitably show up and bring more annoyance.
Eventually, Pokémon Red was beaten, and Pokémon Crystal was put on Twitch. This one was beaten not very long ago, and now Pokémon Emerald will be up in a few days. This is clearly one of the most influential things to have happen for the Pokémon fandom. If not THE most influential thing. Pictures were drawn, stories were written cults were started- no, not that much. Though, to be fair, dozens of memes were created from this. All hail the Helix fossil!
You can see the Twitch here. As for me, I finally understood what was going on AFTER Pokémon Red had been beaten. Yeah, I suck. Before then, I even thought Twitch was a Let's Player. Hey, there are much weirder names out there, it very well could have been!