I still think the biggest problem for Amiga OS4 on whatever board it runs on (as well as MorphOS) is the software. I've had a Sam (and own a Mac Mini/MOS machine) for a short period of time. It is ton of fun setting things up, downloading software, organizing things and all that. But once the dust has settled there isn't much to do, mostly due to the lack of decent software. I guess if you are a developer you will get the kicks from coding your own stuff, but in the end, as a user, although using an Amiga OS machine is fun, it is an end in itself.
Where is the software? You know, things that make computers productive? And I don't mean ports of open source software which I can already download (and run many times better) on my PC. I am talking about new, original software that would make an Amiga experience a complete one. Things like DTP, office, music, web etc... (yes, commercial).
To conclude, I think that there are the Amiga hardware companies out there are concentrating too much on making hardware while not investing anything in software.
Just my 2 cents.