I've got a few potentially silly questions about NTSC capability. Is there a way to get full PAL resolution at 60Hz with NTSC colour space? I live in Canada so PAL video signals are no good for me and my equipment. I don't mind if I have to run the entire machine at 120% speed to accomplish this, I just want to get the full image in a format my displays can handle.
I certainly hope it will be a very successful niche product.
The reason I don't see it as a truly mainstream product is that FPGA hardware is unavoidably expensive, and the average Joe would rather get something cheaper, even if that means using emulation that isn't cycle exact. And that's to say nothing of the legal nightmare that would unfold if it draws the attention of the companies whose hardware is being recreated. Even a baseless lawsuit or C&D order could be disastrous considering how every legal system is weighted in favour of the party with the biggest legal budget.
It doesn't have to be mass market to be very, very successful, though. I see the Replay potentially succeeding in the same way the Amiga succeeded: it may not saturate the entire market, but it will find itself achieving some real success and popularity within certain niches. It's already exciting the Amiga world; there's also the Atari world, the C= 64 fans, arcade and console fans, etc.
The nature of the Replay itself also means it has more potential than simply being whatever retro system you want it to be; it can become any system you wish it to be; retro with modern elements, a convenient development platform bridging two different technologies, etc.
We won't know exactly where and how the Replay will distinguish itself until it has started to ship in real numbers, however, and people get their hands on it and start to mess around with it. That's when we'll see the real excitement and ipotential take off, IMO.