It will be cool for about three months in 2009, and then for 5 years in 2029. But with the demise of Polaroid's instant film, the digital alternative is already on its way: A hand-held, digital camera that prints your images in 20 seconds, the Fuji Pivi.
It's been available in Japan since 2006. You can order it elsewhere, of course, you just have to be crafty. (And it's kind of cheap, actually).