By knowledge base I mean actually knowing your subject. I believe there are only two fields in which having a degree really matters, medical degrees and law degrees. Since these are the only two, I vote overall degrees are NOT needed for most careers fields. I think pretty much every career field other than the two stated can pick up just as good a knowledge base with self study as someone with a degree.
Edit: Since my statements appear to be somewhat misleading I will state an example:
If you had a choice between a 4 year college graduate with no (or little) outside experience or someone with 5-7 years (only college "credit" experience, no actual schooling) which would you rather pick? (I figure 5-7 years is somewhat the "equivalent exchange" conversion from 4 years of schooling since those with experience only tend to start earlier than those with schooling since we all know 4 years is sometimes a bit longer
Would you rather someone building your computer program has years of experience? or years of only college?
I did not state both since I thought it would be overly obvious which person (in most "big business" companies) would be chosen between someone with an equal amount of college + experience or someone with experience only :p