My point was that this exact thing has been tried before, and the market clearly decided it wasn't worth the trouble and expense. This is no different.
Rhombus Tech is building EOMA-68 as a duplicate answer to a question no one has asked in years. By any reasonable standards of modern embedded hardware (I've been working with deeply embedded hardware for my own company for the past few years), EOMA-68 is poorly designed, not tightly integrated, and does not even begin to match the capabilities of many of the embedded modules that are already available at good prices from a wide variety of manufacturers. RhombusTech seems only interested in trying to create and push a "proprietary open source" form factor just to be different. BTW, the Casio/Epson/whoever PCMCIA CPU cards also redefined pinouts, too, but at least they had the good engineering sense to use different specific keying (and to get the PCMCIA consortium to register it as such) to avoid plugging them in where thy could not work, or where they could damage or be damaged by other PCMCIA equipment. Relatively cheap and available (if huge) connectors are about the only thing PCMCIA/CF has going for it in today's world: there's a lot more working against it, starting with lots of wasted packaging space (it was great 25 years ago!), compatibility issues, heat dissipation difficulties, I/O limits, etc.
that's why we also created EOMA-CF which, surpriiise, re-uses Compact Flash. however that's *really* small
No, sorry, wrong. Bzzzt. Thank you very much for playing.
As modern embedded electronics go, CF is simply enormous, rather than absolutely gigantic, as PCMCIA is. Have you actually taken a look inside a modern phone to see the scale of tight integration in these devices? Sure, you can chain yourself to PCMCIA/CF, but you can't do it without also chaining yourself to an anchor wedged firmly in the mid 1990's.
Like the earlier attempts, this attempt to dictate a "standard, open" CPU card form factor will fail - even with "Sparkly Magic Open Source GPL Sprinkles! (TM)" The market moves far too quickly for this - look how hard it is for AMD and Intel to even stick with their own CPU pinout and bus standards for more than a few years! By your logic, I should be able to buy a Core i7 plugin for my old Socket II Pentium computer, and somehow, magically, expect it to deliver all the goodness of a Microsoft Surface Pro despite the fact that everything that surrounds that processor (for input, interaction, communications, interfaces, etc.) has changed even more than the processor itself. Really, what you are proposing (and building!) makes that little sense!
That said, I think standard CPU form factors (even as pluggable modules) are a good thing, but the market has shown that only the most open and flexible ones have any chance at adoption. VIA is arguably the most successful here, and look a their success rate: MiniITX = Hit, NanoITX = meh, PicoITX = meh++, other attempts = Can Anyone Even Remember What They're Called?
Even the well-engineered schemes (RhombusTech's engineering is joke like, at best) that have significant industry backing (I'm thinking Qseven, here) have a hard time getting the required traction, and the pace of innovation and technology advancement makes it really hard to have a standard that's still relevant by the time it's developed and in production. Likewise, something will someday replace the hoary PC-104, but with modifications, it still clings to life as a contender. (And you could easily argue that the Arduino shield implementation is a non-standard "standard" of sorts, although it is not well-engineered, either...) Saying you have a fallback to Cardbus ("we have a plan, here, if it all goes to hell in a hand-basket: we use Cardbus", from your own comment below), is simply admission that you have no bloody idea how to do this right in the first place. CardBus is only slightly less antiquated than PCMCIA, and was itself superceded by ExpressCard a full decade ago!
IMO, even something as simple as a Mini-PCI CPU module would be considerably more attractive than the kludgey and ponderous EOMA-68. Never have I seen such a poor idea with such poor engineering execution manage to grab so much press. When "Sparkly Magic Open Source GPL Sprinkles! (TM)" really are the only argument you can make, you've already lost. I weep for our technology future if anyone actually buys into this steaming pile of crap - As Scott McNealy once famously quipped, "You can put whipped cream and a cherry on a cow patty, but I still wouldn't want to eat it!" EOMA-68 is definitely a cow patty!