1. Death of the AA filter
As sensors this year have gotten bigger and better, manufacturers have been looking for more and more ways to squeeze the maximum amount of image resolution out of them. One solution that has been adopted almost universally is the removal of the optical low-pass filter that prevents moiré patterning. Some cameras found ways around the need for a low-pass filter, such as the Fujifilm X-E2's clever X-Trans pixel array, others simply used massive megapixel counts to bulldoze their way past the need for it. We wouldn't be surprised if in years to come the optical low-pass filter simply became a thing of the past.
2. Rise of hybrid sensors
This is an interesting one. Samsung incorporated hybrid sensor technology into its NX cameras in response to some criticism of their speed, but the standout here is the Canon 70D. The 70D's 20.2MP Dual Pixel CMOS AF sensor uses two photodiodes for each pixel to create an on-chip phase-detect AF system accurate enough to do away with the need for contrast-detect AF during live view. Given the success of the 70D, we have a feeling we'll be seeing more innovative hybrid sensor designs like this come 2014.
3. Packing full-frame sensors into little bodies
Sony has blazed a trail here with the Alpha 7 and 7R, which respectively sport 24.3MP and 36.4MP sensors that are packed into compact-sized bodies weighing around 400g each. The Nikon Df offers full-frame in a little body too, though its 16MP resolution isn't quite so impressive.
4. Larger sensors in cameraphones
As the phenomenal popularity of phoneography shows no signs of decline, the phones themselves are just getting bigger and better in terms of image quality. The new iPhone 5s boasts an 8MP sensor with a 33% increase in light sensitivity on its predecessor, however the granddaddy is of course Nokia's Lumia 1020 with its whopping 41MP sensor (though it doesn't actually take 41MP images - see our review for the full picture).
5. Retro-styled camera bodies
Fujifilm can be held responsible for this one, with its classically cool X-series that began with the X100 back in 2011. This year, however, the trend has perhaps reached its apex, with not only the 1970s-inspired Olympus OM-D E-M1 hitting shelves but also the overtly retro Nikon Df, which emulates the look of the old Nikon F-series cameras (though it looks much better in black than chrome).
6. Android OS
The jury is still out on whether this idea truly has legs, with Samsung's Galaxy NX released earlier this year still being the flagship for a fully Android-equipped camera, and the only one with interchangeable lenses. Samsung aren't the only adopters - Nikon's gotten in on this act before with the Coolpix S800c - but for the time being we'll have to wait and see whether the Galaxy NX truly was a glimpse of the future.