Many many years back, guided missiles wiggled on their way to targets. It was cute, but it was ultimately unwanted behaviour due to a bug. However, wiggling rockets, be they guided or unguided, have a place in weapon design. It's be nice if we could set some wiggles (either patterned or more random,and maybe with options for truly random pathing) in XML. It'd also be usable for down the line when ECM and jamming gets looked at, since that's something that'd be good as a visual indication of a jammed missile.
I figured the wiggling would be good behavior for some smarter types of missiles for the sake of evading (or trying to at least) some types of PD
It would also be nice to have wiggling even if the missile has no target, like a shotgun attack that emulates Diablo's Firestorm.