I think that the main action will be to get Michael McGrath's amended bill through the Dáil as quickly as possible.
http://www.finance.gov.ie/what-we-do/tax/pre-budget-submissions/
If that happens, then EBS could not keep their mortgage rates high for all customers, and attract new business with the 2% cash back.
To be fair to the AIB Group generally, I think that they would welcome a ban on cash-backs. They are only doing it because they have to have such a product on offer to the customers who want it.
Brendan