I also suspect that some of 4e's changes would be a bit odd for the Order. I mean, there are no bards, so does Elan go catatonic until '09? Rogues shouldn't really use bows anymore, so does Haley suddenly morph into a ninja or retcon into a Ranger? There isn't a barbarian, so what about Belkar's recent training? Paladins can't detect evil anymore, but it is well-established in the strip that they can and do.
That looks like a huge list of reasons to convert the strip to 4e to me. There’s comedy gold in them thar hills.