Yes it will. The parts for x86 are cheaper, and it's easier to market/sell than PPC.
The parts for x86 are cheaper, yes.. But when you get right down to it, what REALLY is going to sell AmigaOS to Joe Average Consumer. Hardware or software? Software. You put AmigaOS on the x86 and you're competing with Windows for the desktop. Which operating system has more software that people are going to want? Windows. Same thing is happening with Linux. People are willing to put up with Windows simply because they have access to the software they want.
Will porting AmigaOS to x86 mean increased sales? Of course. Will it makes AmigaOS a success? No way.
Then, fine, do it on x86. Push it to the limits there; the CPUs and motherboards are inexpensive, plentiful, etc.. I caution you, though, not to think of x86 architecture as being related to Microsoft; and to further enhance what you said about what Amigans are capable of (though you said users, not developers there), I'm convinced they could take x86 parts and make it their own. We are, after all, talking of Amiga OS controlling that hardware; not some other OS.
Why shouldn't I think of Microsoft when I think of x86. Here's a blurb taken from the box of my Athlon XP 1600: "When you want extreme performance for WINDOWS XP, the AMD Athlon XP processor delivers." Hardware developers that work with the x86 arch. WANT you to think of Windows when you think of their products.
When you get down to it though, the real problem is drivers. Someone has to write them, and Hyperion sure aren't going to waste their time trying to support all the myriads of hardware out there the x86 world has. Whoever does 5.0 probably won't want to either. Who's going to do it?
By the time 5.0 comes out, it'll be on both (and possibly much more).
Unless AmigaOS gains a significant marketshare before 5.0's release, it won't make any difference how many platforms it'll be on. It won't be popular enough for software companies to give it a second glance.
MG