I just want to point out (I dont know if it already has been, as I havent read every post) But the ratio that they are proposing, is already in use here in NZ as well. And it is working fine.
With the size aircraft being operated across the Tasman, along with the passenger loads (On the current 737-300's) the loads are only around 120-135. This is still well below the needs of 1:50.
The -800's loads will only increase it by another 20-30 pax max.
Personally Im seeing it as a wasted attendant... you dont need 2 up front for business class on a 737.