Well, THAT didn't take long

Impending hotfixes, corruption now updates haste on autorefresh.

Note that no mention is made of crit. Depending on exactly how the change is implemented, it may still be possible to inflate the crit on an initial corruption and roll that throughout. While not quite as attractive, that 5 man ICC trinket can still pack close to 30% crit before it's proc starts to diminish.

This does kill the short lived gravy train of weapon swapping from black magic to a spellpower weapon, though.