So from my POV, most of what we have is OK. I agree with qole that some things that are more or less equal should be treated equally: Being part of a discussion is the same , no matter if it's on t.m.o., on the list or by writing comments for a news item.
OTOH, how are, say, wiki-edits counted? If I add one sentence to a paragraph, is it the same as if I write a 3 page article about secret gconf tweaks?