Using h.264 is a win for bandwidth only if you know what you're doing.  Most encoders out there (see the x264 site for details) are run with poorly tuned settings and generally do a poor job.  And yet ... no one care, they do it anyway.  The idea that marginal 20% or so bandwidth costs are expensive is mostly a red herring.<p>Frankly if Safari and IE were to suddenly support Theora (or Firefox and IE to suddently support h.264), this argument would be <i>over</i>.  No one cares about the technical details.  <i>Any</i> codec that works pervasively will win.