With Intel you have to buy a CPU, buy a north/southbridge. If you want custom interfaces beyond that, that's more chips too.
Not so. Intel has SoCs now. Apparently they're quite popular for use in IVI applications.
Apple has way too much experience being burned by Motorola and IBM both being unable to supply chips in heavy demand.
As I recall, Motorola and IBM had no problem with regular supply. The problem was that Apple was the only major customer for desktop/laptop-suitable PowerPC processors, and those vendors quite reasonably expected long-term order commitments for these products while Apple wanted more flexibility. With Intel, Apple is just one of many customers and while it has less control over x86 processor development it also doesn't have to make such commitments.
There is a hoax running especially in Europe, +358 or similar number, similar to Italy code (+35). Once you get a "ring" from that line or tricked calling it, your phone bill will be doomed. I speak about thousands of dollars (euros) here and you can't get that money back.
As for Nvidia, do they have any chips that fit in the price and power brackets of netbooks?
Hmm, apparently they do, in the form of their own ARM SoC...