There's some folks spouting off about the Polaroid situation. It really sucks to lose your primary photographic medium and there's a lot of subtle points to making film that nobody outside of Kodak, Polaroid, Fuji, Agfa, and a few others really know, so there's a lot of uninformed emotional blathering and wishful thinking.
There's some things that I feel ought to be explained properly. It's not a simple clear-cut problem, there are deep business reasons for why there may be nobody stepping up to fill the void.
Edwin Land left Polaroid in 1980 after his Polavision system was released at the same time that camcorders became feasible. Polaroid took on itself a lot of debit in the nineties to fend off a takeover attempt, which then resulted in their 2001 bankruptcy, well before the digital camera revolution really started to take prisoners.
Saying that Polaroid lost because of the digital camera is naive. Polaroid was in trouble long before. It's funny that everybody thought that Kodak had lost and Polaroid had won the lucrative color instant film market in 1986, but Kodak is much healthier...
The root problem is that instant film is not nearly as cool as people thought it would be.. Even when most people's total photographic output was a stack of 3x5 or 4x6 prints, they still wanted the *option* of getting something printed as a nice 8x10 and framed or copied a few times.
If you have two products, one with a familiar but failed brand name, the other with an unrecognized brand name, generally folks will buy the brand name they recognize. The ultimate example of this, of course, is the Honourable East India Company of the colonization of America fame, who a bunch of coffee traders resurrected in the eighties.
So the current management of Polaroid and their corporate owner very likely sees little use for the declining film business, just the ability to sell low-end hardware for the next 30-40 years with a vaguely familiar brand name and logo.
I have a fairly dim view of this being able to succeed. There are very few cases where companies have been forced to produce something even if it's losing them money. Most of these are coupled with taxpayer support, so I suspect that you'd want to talk to your congresscritter instead of filing a lawsuit and see if they can be coaxed to cut Polaroid's taxes in return for them preserving your form of art.
But do remember that even the fairly interventionist EU was unable to force Kodak to keep developing Kodachrome in Europe, so it's not likely.
Of the various manufacturers, they are the most likely to go for it. They already have all the necessary technology. They make and sell both classic peel-apart film and 600 / spectra / SX-70 styled integral film. So mostly it's a matter of taking their existing Instix film and manufacturing it in 600 format.
In fact, the color quality of Fuji is said to be better. The only drawback is that you can't manipulate Fuji film like you can with Polaroid film... it's too well made.
Polaroid has even sold Fuji Instix cameras as their own in the past.
The business problem is if the buying public... and the people who stock drugstores, camera stores, and grocery stores with film... will accept Fuji branded Polaroid film. It's going to be more economical to Fuji if they just jump into the market without paying Polaroid for branding or a new distributor network or the like. But if this comes at the cost of Kodak getting a bigger display at the drugstore, it might not work out nearly as well.
There may be hidden contractual issues as well.
And the big one is that most of the parts in the Instix manufacturing line are sized for the Instix film and the formula is designed for the Instix speed, so it's not trivial. Unless they want to stop selling Instix film, they'll have to set up a new line of machines. So we're talking about a pretty substantial investment, even for Fuji.
Basically, the bean counters inside of Fuji are going to need to prove that something that Polaroid couldn't make work can be made to work for Fuji. Fuji has so far stated they are not going to offer any new Polaroid products.
One alternative is to just expand distribution of their Instix line of products into the US.
Kodak has all of the technology to make instant film. The very first Polaroid film was actually manufactured by Kodak and they did make a competing integral film that they were forced to discontinue in 1986 for patent reasons. So it would cost them more money to get set up for making Polaroid film than Fuji, but it's still reasonable. And it also comes with the same drugstore-rack-cannibalism risk.
Ilford is less likely to be able to make this work, given that they are primarily known for their black and white films and have basically no presence in the American drugstore market, so they'd be more likely to really need to make a licensing agreement with Polaroid.
Either way, Kodak or Ilford will either need to invest in a whole new set of (generally custom) equipment to make the film and remake the formula.
Ilford has stated that they are in some level of negotiations to make some forms of Polaroid film.
Polaroid has offered to license their Polaroid technologies to somebody else. The best offer would be for them to sell off their business... but since they aren't doing that, one can assume that nobody's really buying. Making film is not a simple thing, so it would be very hard for a newcomer to the market to just hop into the market with a Polaroid license and roar onto the scene before everybody's Polaroid camera is consigned to the bin.
For the 600 / Spectra / SX-70 cameras, very little. They are too closely integrated to manipulate with any sort of ease.
Fuji still makes peel-apart film for peel-apart cameras and peel-apart camera backs. It's not the same look, but it's workable.
If Fuji stops making this type of film, peel-apart cameras should be adaptable to sheet film, if you are prepared to load and unload them in a darkroom.
Personally, I've got a Polaroid Automatic 100 and some 669 that I'm going to use for emulsion transfers and some 665 that I'll use for something. While I can get it, I'll shoot the Fuji FP-3000B film in it, and then I'll probably keep it in a closet and pull it out sometimes with sheet film or something if Fuji stops making peel-apart film.
But it does bug me that I just haven't gotten much usage out of my Polaroid. I thought it would be cooler than it really was.