I'd personally prefer it if people only name their sources when it's vital to understanding the context of the quote.
Look at all the lists of supposed Bushisms on the net - are they really any funnier for being attributed to Bush? I don't think they are (and in fact I think it makes the writer look somewhat silly, but that's a different discussion).
If you're quoting part of a conversation then I suppose it makes it clearer to name the participants - but if fake names would work just as well, why not use them?
I'm not going to start rejecting/deleting/editing stuff for using names, though. (Except of course to avoid personal embarrassment. One of the quotes on this site was actually my own, spoken in a fumble-tongued moment of drunkenness, which as anyone who knows me can tell you, is not an unusual occurrence. No, I'm not telling you which one.)
I suppose the real line in the sand gets drawn the first time we get sued and told to take something down!