BeOS was "the Amiga done right" - according to Jean-Louis Gassée, founder of Be Inc.
yellowTAB's Zeta OS is the successor to BeOS (
www.yellowtab.com). Check out the Zeta liveCD to get an idea of how Amiga might look/function on X86. Quite a few driver issues, as one would expert, but FAST booting, a good collection of applications (GoBe Productive office suite, Firefox, etc.), ports of Linux utils (Bash, NdisWrapper, VLC, etc), and a lot more.
If Amiga moved to X86 right now, it'd have a LOT of catching up to do, not to mention the fact that Zeta is really pretty good. Is there room for two similarly modern OSs on Intel hardware?