When the season 4 promo was flashing through images, a slim, angry man who looked like Charlie appeared.
he had an emo hair-cut and some people on these boards started crying, "Charlie's come back from the dead and he looks emo 'cos he's dead!"
i thought that this was rather ridiculous at the time and now I am 100% positive that the man pictured was Daniel from S4/E2.
He has the same shaped face and the same frame as Charlie, his beard was also a bit like Charlie's flashback from S2.