I think I agree with all of the above. Smartphones are taking over the casual 'consumer party snapshot' camera market. Mirrorless is overtaking the "I want a more serious camera with interchangable lenses, but I'm still not a pro" market. Oly has essentially abandoned 4:3rds (no new body since E-5), the aforementioned Nikon news, etc. I don't think the crops will die immediately - they'll linger for a few years to satisfy customers with existing lens suites, especially if the sensors would be the ones that would end up in their mirrorless brethren - but I certainly think the range of choices in price and feature points will diminsh from each manufacturer. Either CDAF will get good enough or on-chip PDAF will become the standard, with smaller flange distances allowed by either case. Eventually crop lenses will either shrink to the Sony E-mount or m4:3rds mount scale, or the big guns *might* try to introduce a mirrorless concept sized for their crops and continue to use those lenses. Not sure what they'd do for ergonomics, though...different body 'grips' which are more just holding frames for either still or video preferences, kind of like all the tennis racket and steering wheel accessories for the "Wii" controller?
Sony in particular seems to be going as far as adopting mirrorless all the way up to full scale - their SLT's still use a translucent lens but the a99 announcement with the on-sensor PDAF points, as on the new NEX releases - indicates that the SLT itself is an interim step. I know they're not a big player in the FF market, but as A.Y. states they're rapidly becoming dominant in the mirrorless realm (no doubt to Oly/Pana's chagrin, since they pioneered it with m4:3rds). I'm seriously interested in the a99 but I suspect there might be only one more FF SLT from them (one more aimed for stills with ~36MPix while the a99 seems to be a still/video convergence optimum), and then they'll dump the translucent mirror entirely. They may still offer something in an SLR-type body shape, ergonomically...but I bet they abandon SLR/SLT completely inside of a year or so. As long as they keep supporting the mount, I don't care (and they are still spitting out new A mount lenses, which argues they are).
The secondary factor is still/video convergence, which is still (no pun intended) ongoing, and for which AF during video is still under active exporation and development. Here too on-chip PDAF I think is the way things will go in the future. But "pro" grade video seems to be quite accepting of FF scale body styles with appropriate add-ons, pro stills already were. MF still exists as a niche and always will. But both electronics are shrinking (control, buffer, A/D LCD thickness) and integration is improving so the smaller FF bodies rival a lot of the higher-end crop bodies, and the sensor manufacturing has come down enough in price that the delta chip area isn't the huge discriminator it once was.
I tend to agree though you'll see the market converging toward:
- Smartphone/tablet camera integration - everyday users
- Crop sensors in the 2x to 1.5x range - mirrorless prosumer to enthusiast level bodies
- FF sensors - 'pro' camera and video bodies.
- "Big guns" - 4k video, MF stills - the real 'auteur' end of the scale
...which will be interesting for housing manufacturers, since smartphones/tablets will definitely continue the 'touch' trend and be unhousable with control as a result, so the u/w market will contract to the mirrorless and FF scale. I guess in that sense Ike's lineup is the one that may see the most upheaval since they house a whole lot of the consumer PnS bodies but currently nothing in the mirrorless scale.
Current rig: Sony SLT-alpha55 in Ikelite housing, Sigma 105mm f2.8 DC Macro w/ Ike 5505.58 flat port or Sigma 8-16mm f/4.5-5.6 DC HSM behind UWCamStuff custom 5" mini-dome. Dual INON z240 Type IVs triggered with DS51 for TTL mimicry, or DS51 alone with home-made ringflash assy for macro.
Topside, unhoused: Sony SLT-alpha99, Sigma 150-500mm + 1.4TC, Sigma 15mm diagonal fish, Sony 24-70mm f2.8 CZ, Tamron 180mm f2.8 Macro...all the gear and nary a clue...