Now I'm totally bewildered.
Seems like overnight, the driver's side blade magically returned to its proper position, so now I can at least turn the wipers on without them getting hung up on each other. The passenger side blade still doesn't return to where it was before, but at least I can turn them on now.
The thing that really gets me is, there wasn't really any play or backlash or whatever in either arm, so it wasn't just a matter of wiggling them around until they went back into place -- they were pretty solid!
Anyways, even though they're not back to normal, they work well enough, so I guess I'll just chalk it up to UFO's or somethin'. Meh!
Thanks for the replies, guys.