I spent a little time playing around with my current AddOns on the PTR. I use Dominos for my action bars and I was curious to see how it would behave with the dual talent specialization.
I’m happy to say that it seems to be working just as I would expect. The mod retains the set up I created for each talent specialization. Note that this only applies to spells and Items placed on the action bar. Keybinds are action bar specific, and if you want to have a different arrangement of bars for each spec you will need to create a profile in dominos for each one. For the most part, however, you should be able to use this mod without any major issues.