Some general remarks:
Just to be cheaper in the sens of being cheap does not work: nobody so far was able to beat Dell
cf. HP Compaq merger
What keeps companies like IBM ahead, is inovation and research!
Putting OSX on Intel machines would hurt MS, and they would have to react!
You always want to have people who have something to distinguish themselves, e.g. many Mac users
with Intel you loose it. Then probably a new company would come up, to give that feeling back.
However, it is true, that Apple has to work on some issues hard.
The screens they are selling in their notebooks are outdated, and those of the iBook are really bad.
In science and education, there are still a lot of apps that are not available for Mac (just check it out on Amazon)
Further, many people in research have notebooks which are either from Dell or IBM.
The story of Apple in research and is highly overrated; Europe is PC based.
Sadly, in the last time Apple induced a lot of negative press and not many convincing solutions.
It would be better, they focus on core things, like
bringing a new OS, that represents the future. So far, that did not happen!