The FPGA Replay will no more 'kill' the original MiniMig board than the release of the Amiga 4000 'killed' the Amiga 1200. It's simply a new option for us to choose from. The Replay complements the MiniMig, it doesn't make it redundant. The Replay will appeal to those of us for whom the original Minimig board was 'not enough', in the same way the Minimig will appeal to those who don't need the extra functionality/abilities of the Replay and are more concerned about getting their 'retro Amiga kick' on a budget than they are about expandability or high-end features.
It market terms, the Minimig is like what the A500+ used to be: a low-cost budget machine above the original Amiga 500, whereas the Replay is the Amiga 1200: the powerful and expandable mid-ranger, whilst the NatAmi is like the Amiga 4000: it's high-end in features but it has a price tag to match. NatAmi will be the most full-featured option and will offer the users most out-of-the-box, but it will also be the most expensive option of the three, because it will offer many features which most people may not even want or have a need for (do we really *need* a full 512MB of RAM, plus IDE support and a floppy disk drive, when we've large SD card capacities now, and can simply ADF up any disks we wish to transfer over and use?)
The Replay is ideally placed in between these two. It leapfrogs the original MiniMig in specifications, offers AGA and 030/040+ speeds, and is much closer to what the NatAmi will offer, whilst keeping costs down by removing unnecessary features which aren't required by the average user. Thanks to it's daughterboard expansion slot and FPGA design, it can also be expanded in both software and hardware capabilities in much the same way an A1200 was expandable into something which could not only match, but even exceed, the out-of-the-box capabilities of the top-of-the-line A4000.
From my point of view, the Replay offers the perfect balance of power, performance, features and expandability and most of all, it does all of this at a very reasonable price. For those who only want A500 capabilities to replay old Amiga games at the cheapest possible price, the original MiniMig design still remains the best option.