Pentax refined one of its earlier concepts at Photokina 2006 with its X-Change camera, a project started way back in 2002. The idea combines the best of both the digital SLR and compact camera worlds, with interchangeable lenses packing integrated CCD image sensors inside.
As soon as this technology can be perfected, you might not need a huge camera bag any more if you want to take along a highly-capable digital SLR with interchangeable lenses. Cramming CCDs into such a small space can't be cheap, nor can it be noise-free. Maybe that's why this concept is taking so long to bring to market. What do you think, commenters? Is it vaporware?
Pentax X-Change concept in the works [LetsGoDigital]