HB4717A34, I am afraid that sort of implementation is impossible. Coding logic for every single encounter in every Cataclysm raid and the appropriate backup logic (is the other tank dead, etc) would be a gargantuan task that would take a very long time. However...
edit: perhaps I could implement something like only tank your focused mob, or do not tank your focused mob. I will look into this.
Jilles and HB4717A34,
The experimental version I posted at the top of page six (this page, I believe) named DoctrineBTtest.zip does not include taunting nor buffing. This means that, if you are working on an encounter that requires tank swapping, you can simple disable righteous fury when the second tank taunts from you, and enable it again when you manually taunt back. This version does not include any targeting code either, which means you can tank what you want -- simply select it, move towards it, and let the CC do the rest.