There probably already are some cameras out there that use flash memory (thumb drives) for memory, but I haven't come across a single one.
All digital cameras should use flash drives. Then you can use any existing flash drives for more memory, simply plug it into any computer, buy bigger memory cheaper, and lastly not worry about Sony, Samsung, or some other camera company discontinuing the memory line. Oh yeah, you also wont have to worry about having a special drive on your computer to read flash memory.
This sounds like a pretty good idea, right? There's so many great benefits to it, and the only downside to it for consumers is if their flash drive is huge, it might not fit, but even that can be fixed easily with a little ingenuity on the camera designers side.
So why isn't it being done? Well, the camera companies don't want it because they sell their own proprietary memory to make sure they can make an extra profit off of you. Sure, they may have to sell the cameras for a few dollars more to get that money back, but even still, it will be worth it to the consumer who can buy incredibly competitive flash drive memory in place of it... As long as the salesman or customer know the benefits of thumbdrive memory vs proprietary. When the thumb drive is up to a terabyte, I doubt any camera company will be spending the time to keep the space size available on their proprietary memory comparable.
Camera companies should start producing digital cameras that accept flash drives. It may have been 5 minutes easier (from the start) to make proprietary memory, but cover up this problem by taking 24 hours for the consumer and make your cameras "flash drive ready." Use those words in describing your product and any slightly techy consumer will appreciate it right away. What's the point of developing predictably dead-end technology anyway? lol.