For example this: http://store.apple.com/us/...
It certainly has more horsepower than the X1000 but it probably won´t run UAE any better than your other PC.
Since UAE can only use one core, it will depend on the speed of the individual cores for UAE's speed. The good thing is, we hit the minimum core speed to run OCS/ECS/AGA Amiga games awhile ago. Lets face reality, if your not using UAE for games, there isn't a whole lot of Amiga 68K apps that require heavy CPU usage.
Since most Amiga folks don't mind building their own system (be it x86 or PPC) let look at what we can build ourselves. You can buy a AMD six core plus mobo for under $400. Next year who knows how much CPU power (plus mobo) that same $400 will buy. Problem is for AROS/MOS/OS4 is that the SMP horse (x86_64 and ARM) left the barn years ago and isn't coming back. AROS at least runs on x86_64 but can't be SMP while OS4 wants to be AMP, it's on PPC and AMP will never be SMP without a massive rewrite. OS4 rewrite for SMP is highly unlikely to ever see the light of day. Basically we, the Amiga Community, are screwed for not being creative enough to adjust to the ever changing environment with rigid 3.1 API dogma. Shame really, we use to have pride on what our beloved OS could do that Windows/MacOS couldn't do at the time. Now the tables have turned and there is no way out for 10+ years of near sighted mistakes.
And people expect to sell a ~$3K USD system that is in danger of being eclipsed by smartphones and is unlikely to ever fully be used by OS4, in these economic times? Yeah, right.