It is not about MOS either. It is about Trevor blog, where he mentions Amiga OS a lot, he even mentions Mac. I see no mention of MOS though, he does mention Amiga like OS's. But as far as I can tell that is it.
Of course Trevor has mention Mac (after all, what do you think we run MorphOS on).
I've been in contact with Trevor several times, and now that there is no longer a direct Hyperion/A-eon connection, I don't see any reason why an X5000 MorphOS port isn't possible.
But do you really think Trevor would mention that in his blog until it was firmly committed to?
Personally, I think the SAM460 port was announced prematurely.
On another note, I wish Trevor would tell us a little more about their relationship with Varisys, I have always been impressed by Paul Gentle and company.