I think that they are a measure of how much you participate in the community here. I've been a member for 6 years, but as I usually lurk, my karma is low. I don't use karma as a measure of other posters but I can see why the management locks certain features for those with higher points.
> I hope not
Why?
I appreciate karma points as a measure of how much my thoughts resonate with others, or don't... They are real enough for me.