There was a sort of beta release of the A1X1K, so that developers and testers could put it through its paces. The OS still doesn't support the hardware all that well, but AmigaOS 4.2 is supposed to fix that. It's an interesting machine, but it's very expensive for what it is.

There's also the Natami project, which aims to create the ultimate classic Amiga using an FPGA. There are other FPGA Amiga clones, like minimig and FPGA Arcade Replay, but they're mostly intended to recreate the old machines, rather than expand on them.