Well, as for myself I'll get the A1 when OS4 has arrived. And why? Because mostly of nostalgia, the second for the FUN. If OS4 is capable of running my old amiga games (in ADF I suppose since we got new diskdrives nowadays..) and applications problemfree as well as new software then I'm happy. Currently I use an AMD 2Ghz computer to run new games on and WinUAE. I use my real A1200's just as often, and the only reason I got an AMD in the first place is to play the new games, like Falcon 4, FS2002, Unreal Tournament and so on... but if I got a computer that was running AmigaOS natively without emulation and that could do the above stated, then speed isn't a necessity. I will still have my PC next to my Amiga, but only for gaming and 3D design. Everything else I would be doing on my Amiga.
Finally, to me fun can not be measured in money. Sure, the A1 is expensive, but it's WORTH it when comparing to using a machine running Windows.