I am amazed at the >2gb comment, understand it with Vista though, I run Windows 7 on a netbook with a single core atom and 1gb ram and it flies.
Yeah, it must be Vista he's talking about...
But MorphOS to me is more polished than Aros but Aros IMHO has the best potential future and already has parts the others lack.
Yes, AROS has some interesting parts that MorphOS lacks (even more so if you look at the bounties as "real features, just not quite here yet"), but it certainly goes the other way around as well, and I mean real features which goes beyond any level of "polishness" (as I'm sure you know, since I watched your great videos!

As for the future, all we can say about it is that it's unknown, right? MorphOS "management" (is there any?

) doesn't communicate on any kind of road map they might (or might not) have. AROS is AFAIK a bit more anarchistic in its development, right? But both OS's are in the hands of enthusiast developers, and I'm sure development for both will continue as long as there is an interest among them to do so.
If you build your claim about potential future on CPU architecture support, I wouldn't claim it's cut in stone that MorphOS will be PPC *forever* (unlike OS4). AFAIK, none of the developers has suggested it would; instead they have shown quite a realistic view on the matter IMHO, judging by the public posts I have seen from them...
I like AROS BTW, and I like the idea and philosophy behind it!
I'm even thinking of chipping in some money in one of the bounties, probably the wifi one...
