True, the PC is boring. But it is darned fast and dirt cheap! The common user dont care about the actual hardware, they care about the actual software, how the beast looks and the very important price.
What the Amiga needs is cool software not found on other platforms and cool software found on other platforms. An idea could be to port OpenOffice 1.1 or 2.0 to OS4, since it would provide a whole host of features to the platform it so sorely needs.
A new set of expensive custom hardware? I don't think it is worth the investment. A custom design of the casing? Definitly
A custom keyboard? Oh, yes. (it is darn easy)
ColdFire? Oh, no! Use Intel-architecture (it is dirt cheap, mass produced and darn fast (yeah, I know this one aint popular))