It looks like there's some good news for Black Temple and Zul'Aman raiders out there. Tigole has announced that a hotfix will be applied to live realms that should keep a bug from occurring during the Mother Shahraz and Nalorakk encounters.

Here's the announcement straight from the World of Warcraft forums:

Nalorakk and Mother Shahraz will no longer haste their attacks following a parry. A hotfix is being applied this evening to live realms. These encounters had been set up to not haste after parry for some time, but there was a bug in the implementation which we have identified.

The fix should be up soon.