Okay, this is just too cool not to mention...
Crave has a story from Demo 07 on a new invention by a startup called Zink, with Polaroid's help, is making it much easier to print photos without a large inkjet, thermal, laser, or other ink-based printing mechanisms. Think of it as a new millennium version of the old Polaroid paper. The paper itself is a polymer that has multiple color layers that are heated by a print head to create the actual colors. Here are more details from Zink. This means that rather than a separate printer from your digital camera, you could actually integrate it right into the camera, as well as other devices such as laptops, UMPCs, iPods, etc. Purely brainstorming, you could even integrate it into home electronics equipment like your TV -- there has been at least one attempt at integrating an inkjet into a TV before -- even your fridge (for that list of stuff to get from the grocery store). The limiting factor is having enough space to store the size and quantity of photo paper in the device.
(courtesy: Zink, Crave blog)
Of course, this is a different business model than what HP and other companies have. Most printer companies focus on the financial side of selling ink cartridge's rather than the printer itself to make the most money. So printers have become relatively cheaper with technology and ink much more expensive. Here the model still exists but the paper itself may be the profit margin. Zink suggests 100 sheets for US$19.95. I can't tell who makes the paper but I can guess that Polaroid might just get a new lease on life here.
The question remains if you still have to wave it around in the air for 15 minutes before you can see something visible on the paper.