uh, correction: even though there are some fluctuations and uncertainty in "zaphod" support in X, it looks like that bits are in place, at least for Ati/AMD. the bigger culprit are DEs, with KDE in particular which since 4.0 becomes all garbled up and unusable with "zaphod" configured. and promptly dies or worse, drawing horrible stuff. can't say about Gnome.
and here i'm offender too. being so pissed i can't even write straight to their bugtracker. they have broken so much intentionally, for "greater good" and shit. but it's even bigger off topic.