This question was born from the discussion in comments under this answer.
Чё is a slang/colloquial word, but does it mean что or чего? I believe that it's the equivalent of что, although it can't be substituted in all cases - and I used this in my answer to the linked question. However another user stated that I was wrong and that the correct meaning is чего.
So, which meaning is correct?
UPDATE: I was suggested that it can mean both, e.g.
Чё тебе надо?
Что тебе надо?
Чего тебе надо?
However in this case I would say that in the last version (чего тебе надо), чего is in itself is a colloquial from of что, hence can't be argued to be the meaning of чё.