i think it's important to note that the cube and newton were not bad ideas by any means. the newton led the pda revolution, and the cube is damn near the same thing as the mini. they were both wonderful devices.

the point that we have to realize is that some of apple's significant failures, such as the cube and newton, were products of bad timing. the market was simply not ready for those devices, particularly at the price point they were at. apple was still innovating, but we didn't see the rewards until later (in some cases other companies such as palm, etc, and in other cases we see apple winning now with the mini).

it's the same reason why NeXT failed but OS X is succeeding, bad timing.