Unfortunately, Hyperion are restricted by their license agreement and can only allow OS4 to run on AmigaOne hardware. Until this restriction is lifted/modified, the only way to (legally) run OS4 is on an A1. OS4 on a Mac Mini would be wicked - but it's just not going to happen at the moment.
This is only true in countries where such laws applies, though. If OS4 will be commercially available with an EULA stating it not to be run on anything but the A1 hardware, you don't really have to obey this EULA in your home unless the specific laws of the country tells you to. In other words, if there would be a way to 'modify' OS4 to run on your Pegasos, your Macintosh or whatever PPC hardwere... it doesn't necessarily have to be illegal to do it.
Modifying your legally obtained OSX to run on your ordinary X86, for example, may be perfectly legal, depending on where you live. Just like using OSX under emulation. Or whatever.
But I have no clue whatsoever what laws apply in which countries...
The sad thing, though, is how restriced Hyperion, the developers of the OS, is... due to the idiotic license (sorry, but I really think it is an idiotic license). Not that I can say that Hyperion feels ready to release OS4 commercially as of today... but when they do, it is really a shame that they can't (if they can't, because, in all honesty I don't know what the license says).
To sum it all up: if the license says that Hyperion isn't allowed to release the OS to be run on other hardware than the A1, well, then they can't release it to other hardware legally (obviously), but as an end user; RUNNING the OS on other hardware does NOT necessarily have to be illegal.
Oh.
Well.
Boring story, in whatever case. I'm pretty calm, not bothering about it at all, at the moment. Thankfully. If/when it will be released... well, that is another story.
Oh, and I have to add... what happened with Troika's promise of more regular updates on what's going on?