There's a whole section of what makes the OSR so important that I haven't seen tackled elsewhere so I'll give it a ranting shoot in here. When I started to play (Holmes D&D), I was but a kid, and a very small one, and for kids, man, the road to D&D was a harsh uncompromising one.
Because the rules, the system and the people all expected that playing D&D was like following a progression curve that would eventually lead you to design D&D. You started a player, then took a big step forward and became a Dungeon Master, then had, yes had, to write your own adventures. Only then were you considered a complete player and accepted as such. Now, writing adventures when you're 8 to 10 years old can prove tricky but yes, I did.
We didn't have the internet back then so people with a little more craft would handwrite or type their adventures, put some picture on the cover and go xerox all the way to "sell" them around for a handful of peanuts. Every club, every city, every place was a bustling underground network of DIY publishers and THAT WAS PART OF THE GAME.
Now that we have the internet, our virtual city has different venues. It has Indie Press Revolution, Drivethrurpg, Lulu. I bet you know those names. But deep down, it's the same story, it's where we share this part of the game where we become designers, this part where we reach the full extent of what D&D is, turning us all into writers and game creators.
To a player, the release of D&D5, with or without OGL, or the decisions of the other system owners (think Lamentations of the Flame Princess or Dungeon Crawl Classics) is probably good news and won't change much of the way he games anyway. But to the designer intending to release his tidbits on the internet, to the complete D&D player, the way the industry goes and especially the level of creative freedom - either legally or in the nuts and bolts of its system - it allows him is far more important. We're all stars now and we might need to struggle to keep intact the design & release side of the OSR for I don't know where the 5th might lead us, nor do I know what decisions the big boys are going to take but I know for sure that we need that space or else, it isn't D&D anymore.