That is the thing I don't get about how vicious some people seem to be about CUSA. Nothing that CUSA is saying it will do is outside the bounds of what is possible. Certainly it is easier to do than what MorphOS, AmigaOS or MiniMig have done. If CUSA was promising custom hardware, or a new OS from scratch, I would be a lot more skeptical of them, but what they are promising is well within the reach of a start-up business. Heck, it is well withing the reach of a few good hobbyists.
The biggest and most important key factor though is whether they have asked for money. As long as they have not failed to deliver a product after collecting money, the worst they could be accused of is being big talkers. That puts them in the same league a as the RetroReplay, and the Natami. And I don't mean that as any kind of insult to Mike, or the Natami team.