There is some evidence that some Basiji are switching sides. It's not very conclusive yet (video and photographic images, with as yet untranslated sound), but here's hoping.
(h/t, of course, Andrew Sullivan.)
Supposedly, the following video includes the Basiji asking for forgiveness.
BREAKING UPDATE: As I was typing this, Andrew Sullivan found that the picture and most of the one's like it probably are just one event. We'll see if it becomes more widespread, but as of yet it's not.