The 35mm format is least likely to get much use by me with my production firmly entrenched in medium format. For many years it was my bread and butter format producing images to the Ilfochrome Classic media, and by comparison with medium format, it is much harder to do it well in 35mm than larger formats, with automation a major hindrance at times.
Today my elderly EOS 1N, more than capable of munching through 36 exposures in 2.8 seconds (3 seconds, then!) is relegated to the occasional happy snap or B&W use.
I share the view with Maris, above, that 35mm will be the first format to disappear, leaving just medium format and a selection of 4x5 (LF) sheets.
Medium format cameras have been cheerfully detached from the march and progression of automation and technology built into progressively more and more 35mm SLRs: consider, for instance, what lies within a Nikon F6 (still a 35mm camera, after all, loaded to the hilt with technology), and then put it beside a Hasselblad 500CM.What do you see? One is a photographer's tool for creating his vision free of the floss of technology, while the other would be right at home, and entirely capable, shooting sports, wildlife or portraits. The F6 has its own meter and can think for itself. The 500CM requires established knowledge of hand-held metering in many, many circumstances. Once you have tapped your inner potential for working and thinking independently of technology in a camera, and creating work that makes people stand up and take notice, there is no real appeal to the 35mm format, not much bigger than a special edition postage stamp as it is.