Well, due to the recent change to imp LotP this problem is solved, but without that mana reg, we would not be able to shift to get out of snares (maybe only Novas) anymore 'cause we might need some mana to throw out some heals aswell.
Btw that were just some thoughts, don't flame me for it, there are enough 'Zomg lulzed omfgzor'-idiots around.

Besides Barkskin now is fully confirmed to be useable in all forms.