This is true, the smart money may be on used Pentax gear if/when newer models come out, though I think that the update cycles for this level of equipment are a lot longer, so we don't get to answer that question for a few years. Of course, I look at the concept of reducers, for now, as a novelty, but an interesting one. We know they've been used built-in for at least some lens designs.
It would be really interesting to see some f/2.8 standard zoom designs reformulated into f/2 APSC designs. With an extra stop of brightness, and 50% greater spatial resolution, they would bring essential parity to APSC platforms relative to 35mm, when using the standard zoom lenses. Would look like this:
APSC kit:
16-46 f/2
50-135 f/2
35mm kit
24-70 f/2.8
70-200 f/2.8
Roughly equivalent FOV and DOF, probably just about the same size/weight lenses and maybe even bodies, and I wouldn't expect the lenses to be any cheaper either. That said, if we saw such lenses, I think that wold be a strong indication that 35mm full frame remains expensive for some time to come. Not that it's too expensive for what it is, but perhaps that it's too expensive for the update cycle of contemporary cameras - and they become more like medium format in the marketing as well. It's nice that some well heeled amateurs, moonlighters and hobbyists bought 5d-d700 level cameras, but having those around gives pros a cheaper alternative, and that may not really be a good idea. Those guys can and will pay, so they'll just make them.
Most of the current crop of full frame cameras utilize one of only three sensors. Nikon's 12MP, Sony's 24MP or Canon's 21MP, and all have been updated far less frequently than their APSC-m4/3 brethren where there are 12-14-16-18 MP sensors in 2X, 1.6X, 1.5X and 1.3X
Rumors now suggest a forthcoming
25MP APSC Sony This has nothing to do with any possible high speed APSC zooms, just shows that the update cycle for APSC is faster at the moment. We might see 30-40MP full frame sensors soon as well, then all this means nothing.
Right now a pre-level APSC body costs from 1200-1800. A pro level 35mm goes from 2500-7000, but at the bottom are some compromises. 5ds2 has semi pro level body on a pro level sensor, D700 has it the other way around. A fully pro-spec 35mm camera body starts at 5000.
After a fashion it makes sense to sell high-level, expensive APSC lenses and relatively cheaper APSC bodies. Lenses I will keep for a long time. Bodies I will recycle every 2-4 years... I don't believe that the price differential between APSC and 35mm should be so great, but maybe it is, and maybe that's where the manufacturers want to keep it?