There is a gameplay design team that is currently working on new features for the All-Star promo. They are limited in what they can achieve because gameplay changes need to be made through client updates unlike that the content deploys which are done through the server. And Brian was quite candid in stating that gameplay changes are low on the priority list given that it's difficult to draw tangible revenue benefits from them compared to new content.
That's the sad part.. Improved game play = improved revenue for the long term. Less turnover of users, more long term customers that will micro transact as they are already satisfied consumers..