Majastas A600 accelerator is now being done by @biggun here? and Cyclone-5 being the descendant?
Has the source for the FPGA Arcade come out yet? I think it's a great platform. But stuff that actually gets used is even better 
Majsta is working with Biggun on the accelerator project because the original softcore used in the A600 accelerator was not as fast as the Phoenix core developed by the Apollo team (which is lead by Biggun).
I suspect that (based on previous conversations and threads on various forums) the new Cyclone 5 based accelerator is just a 68000 chip socket harness for the Sockit board and other harnesses are in development for other Amigas.
The FPGA Arcade Replay board is only in tester's hands right now. I wonder how likely a Replay board add-on version based on the Sockit would be, given that the Cyclone 5 is likely more advanced than the FPGA on the Replay board. I'd love a solution like this because it would free up space on the Cyclone for MMU and FPU while freeing up space on the Replay board for better graphics card emulation. ;-)
