Well, for what I can remember, Elbox had a working prototype that they showed on some Amiga meeting. The performance was of a low end 68040 because they had to patch many executables to make AmigaOS work. So they canned the project due to compatibility and low performance results.
Elbox are still alive, re-releasing old Amiga hardware designs every now and then for a quick buck.
Perhaps by following what the Atari Coldfire project did, the Dragon could still achieve some success. These Atatri guys simply used some very interesting tricks: they ported their OS to the coldfire, created something like coldfire.library to get some compatibility, and developed a 68k jit emulator. It is not 100% compatible, but it does work nicely.
I still think the same aproach Atari guys did, using Aros, reusing the same 68k jit emulator and coldfire.library could produce a viable result. It is much better than hanging to new low end 68k accelerators, or even old & expensive 68060 ones.
But then it is just my opinion...