No. Canon's 1.4x solution isn't really a solution if you cripple the ability to use it.
Totally agree on that one. On the product pages of the new 500/4 II and 600/4 II they show the MTF curves of lens + 2xIII, just to show how relatively great they look (and in fact, the MkII lens + 2x curves don't look all that different from the MkI bare lens curves). But that's almost false advertising, as they took away the ability of the 1-series to Af with those combos.
The weight issue makes sense. I ran into an prominent birder (author of several bestselling bird guides) on the top of a mountain (literally!). She has both a 500L and an 800L, and uses them when she can drive to her location, but for hiking she uses a 300/4 + 2x on a 1D IV because that's a carryable combination that will still AF.
Think they might release a 1DmkV-like thingie with f8 autofocus ever?
I do think there will be some backlash over this. There already has been, in fact. Prominent bird photographer Art Morris (who's also a
Canon Explorer of Light) was "
stunned" by this issue.
Obviously, no one knows what Canon will do. But if I had to guess, I think that if they apply the same circuitry improvements (and maybe a few more) to an APS-C sensor, they might release a pro-style (integrated grip, fully sealed) APS-C body to fill the gap left by elininating the APS-H line. If they do that, I expect that body would retain AF at f/8 (perhaps even with more than just the center point).