New limited batch in the works! Who knows which FPGA gaming solutions will
actually ship, or when, or how they will turn out - with MiSTer you know what you're getting. I too was tricked into thinking something was pretty imminent about a year ago, so I didn't make more expanders - but as I've gotten a few requests from operators to make more board, I'll give it a go.
I should be getting the boards just before I leave for a 6 week trip mid June. If you miss the first 'window' sales will reopen in August, pending availability.
I may do a hidden purchase link for those on the notify list, and even if I don't, the order window will be very tight - so if you're thinking about getting one I recommend signing up for a notification at
https://irkenlabs.com/product/jamma-expander/
These are of course the rev 2 with USB hub and fancy cables (that also does a seppuku if connect the JAMMA connector upside down - so please use a JAMMA key...)