That's not going to work as an opensource project. That is going to take way too much time for which you won't find enough spare time programmers.
Linux got only this far because it is sponsored on a yearly basis by millions of Dollars. Either because people are employed at companies to work on Linux related stuff or via other constructions.
Complete operating systems and programs running on it can not be created by merely open sourcing it. You still need a shit load of cash to have full time programmers working on it. That only works for Linux and nothing else.
First of all, I didnt say anything about Open Source in regards to what Collas and Gateway were doing back in the days, and MorphOS is also not Open Source. I was just saying that IT'S TOO LATE for AmigaOS type OSes, closed source or open source is irrelevant.
Secondly, you're wrong that creating new OS is so unthinkable that only Linux manages. There are lots and lots of opensource OSes around, many of them (most) far more complete and capable than AROS, and an OS being open source does not exclude commercial participation, like how you said for Linux. And Linux is _not_ the only OS around that benefits from both commercial and volunteering developers, the same can be said for the BSDs and Solaris, and even opensource elements in OSX and Windows.
Thirdly, the only thing I care about making opensource - or rather, to be put in public domain with sources and all for anyone to hack - is classic m68k AmigaOS, not because I expect lots of developers to jump on it, but because of personal interest, being able to make small improvements without having to disassemble and guestimate what's going on, and because we could finally get rid of all the hypocrisy and fuzz regarding "piracy" of kickstarts and old OS disks.