chrishajer: Ah, sorry. mod_rewrite
timskii: I could have sworn they had it turned off at some point, but maybe I am misremembering. The point is that hosters tend to do stuff like that (often without warning), so as robust a solution as possible would be ideal, naturally.
*I’m a designer, not a coder, so I’m mostly talking out of my ass.
Considering most people are probably on shared hosting, and hosts like to disable random things for their various nefarious reasons (in the name of security, usually), I would say keep on supporting both if possible.
I know DreamHost, for one, has it turned off.