I hear this sort of gloom and doom all the time, I don't believe a word of it.
For a long time, whenever anything even vaguely bad was announced on gamingreport.com, somebody (probably the same person) posted that this was obviously the end for WotC and "in six months we'll all have a new hobby" since D&D will be cancelled and without WotC the RPG industry will collapse almost instantly.
When 3e was coming out, one of my friends couldn't believe they were dumping the venerable AD&D for this unproven new "d20 System", he believed it would fail miserably (no Demihuman Level Limits? Clerics who can use swords?! 8th and 9th level Cleric Spells?!?), he called it "The Edsel of Gaming".
Of course, back in the 80's people feared that the religious right would spell the end of TSR. I remember growing up hearing preachers say they were going to sue that "satanic company" to put them out of business for selling satanic books to kids.
In the early 2000's, I heard people say that pen & paper RPG's were obsolete, and "in the future" RPG"s will only be played on computer: ala Neverwinter Nights or Everquest, and that people who still used dice & paper were just trying to evade their eventual extinction.
Bull.
If it all collapsed today, if the doomsayers in that other thread were right and Mattel bought Hasbro and shut down WotC outright, if everybody at White Wolf had a collective angst attack and had permanent writer's block, if Palladium lost it's last fan by suing them, if Steve Jackson went out of business because of another botched raid by the Feds, if Gen Con announced that there wouldn't be a con next year because of administrative/legal/scheduling problems. . .
We'd still be gaming. Fans would still be making games and selling them to each other, eBay would be rife with game trading, campaigns would go on. The kids of current gamers would be taught to game, and we'd still recruit new people to the hobby just like we all have. The OGL gave the D&D engine immortality, and the concept is immortal.
I like WotC publishing books, but to be honest they aren't making what I want. I want more Star Wars RPG books, I'd like more d20 Modern support. I've got over three dozen 3.x WotC D&D books, not counting previous editions and 3rd party stuff, I could run D&D with just that for decades without a problem.
Many people just like to whine Gloom & Doom. It is just basic human nature, and you have to learn to recognize that.