As always, apple won't make a device that people want unless they can make a packet on it or tie you into more of their services.
It took three major os revisions on iPhone to even include copy and paste. My mac mini still doesn't have a powered mic port.
Plastic MacBook won't have FireWire otherwise the is no Major reason to go to a 13" pro.
iMacs won't put quad core into the 21.5" other wise there is no reaon to by the 27".

Apple are doing just fine selling low volume, high value pcs. As long as they don't become irellivant they will do fine just the way they are.

I run nearly the same software on windows and Linux as I do OS X so a cheap Linux netbook is fine for me. But it would be nice to have the same os on everything.