Suffice to say that the DIL socket is key to Jens's solution, and that it has to have a harddisk interface if it ever hopes to sell or even compete.
Likely he doubts the market (for certain reasons), a misplaced doubt in my opinion partly due to the fact that his accelerators has sold well (no, I don't have any figures), and the _potential_ market is larger, if done right. (A500/A500+/A1000/((A2000))).
My thinking is the same as Amir expressed. A tiny card with "any" cpu, harddisk interface and 4MB fastram will be a good selling point for all the above models, if better or lower priced than the two others being developed by others now. Even all 3 developers might be needed to satisfy the demand to throw out irky old cards and side expansion, who knows?
My personal hope is a tiny card with just SMD 68000+harddisk interface to plug an ACA630 into. But very likely that solution will be discarded, sadly. Unlike A600/A1200 there are reasons for not abandoning a 68000 mode for these platforms.