Yes, and we can also start topic "What happens after ISO 400 is gone?" and "What happens after ISO 100 is gone?" and so on. You can't deny it's happening.
And, in the end, the whole planet Earth will be destroyed. You can't deny that, either.
We will all die!
I hear that the midwest United States will not be able to grow wheat in 40 years, because of climate changes and water shortages. Destroying the Earth would be taking the easy way out. No one ever got ahead that way.
No, it's a little different in this case. I don't think ISO 400 or ISO 100 have anywhere near as high a chance of going away. Simply, they're less expensive to buy, so more people can afford them. And they keep way better than the higher speeds (800 and 1600).
It looks like 800Z is going away (I just bought a bunch for a major project I'm doing this summer, so no big deal). Portra 800 has increased in price to between $7.50 and $9.50. Superia/Press 1600 is still available for the time being and still around $5 per roll. Same with Superia 800...still made. However, with Fuji stopping the manufacture of 800Z and the price of Portra 800 increasing 30-50%, I have to wonder if enough people will be able to afford it to keep it in production. I know I won't be able to buy much of it, so I'll likely switch back to Superia 800 and 1600. Kodak has no obligation to continue making a fast color neg film if it becomes unprofitable...even if they're the last man standing. Remember the tungsten films? Now that Fuji T64 is going away, there is no mainstream option left. Tungsten film, except for motion picture stocks, is history.
Professional 100, 160, and 400 speed film is much more affordable. Look at prices for Ektar and Portra: they range from $4.50 to $6.00.
I wish I could afford Portra 800, but at $10 per roll, it's not going to be something I can use in mass quantity.
I'm really convinced that the solution here to keep these products in production, is for those of us who do shoot professionally, or shoot rare gigs, or whatever...is to shoot film in addition to or instead of digital on paying jobs whenever practical, and pass the costs on to the client. Unless one is rich, hobby or fine-art shooting isn't likely to be sufficient alone to keep every type of film on today's market avilable for the next decade.
I think the following color films are in the most danger currently (not in any particular order):
Portra 800, Superia 1600, E200, Elitechrome 200, Sensia 400, Sensia 200, Astia 100F, Velvia 100F, EBX-100, HD-400. This assumes of course that 800Z, 160S, and 160C are actually already in the process of being done away with.
I think the following are relatively safe because lots of people always seem to use them: Velvia 50, Velvia 100, Provia 100F, Sensia 100, Provia 400X, E100VS, E100G, Elitechrome 100, Gold 100, Gold 200, Max 400, Max 800, 400H, Portra 400NC, Portra 400VC, Portra 160NC, Portra 160VC, Ektar 100, Superia 100, Superia 200, Superia 400, Superia 800.
Once a few more types are discontinued, I think we'll be safe for a while. I just hope that the one remaining pro 800 speed film is not one of them. The whole point of this thread is to prepare alternate methods in case.
BUT I have recently discovered the pleasure of medium format 6x7 and with much slower maximum apertures, when shooting outside a studio, faster films can be a boon. The quality of the RZ/RB lenses is so high that shooting at f45 or f32 can reveal incredible detail throughout the huge depth of field. I used a lot of Fuji 800 stock just for this purpose and I really miss it in medium format. 
Indeed trying to find 400 film in 220 format over here in the UK is getting a lot tougher...
