I think diminishing returns stayed the same in 1.2 and I had read previous on sithwarrior.com and Dulfy's page that 400 crit, surge, and alacrity was what to shoot for, in that order. Once you get to 400 on each of those 3 stats, then you want to just max power. (This was for my sorc healer)http://dulfy.net/2012/03/22/pvp-gearing-in-1-2/
Looking at the stats that are available on bm gear you won't be able to get all 3 to 400. So i'd go crit to 400, and then a toss up on surge/alacrity (I don't know how much of your spells are cast, or if alacrity is a stat that is good for a commando) then power.
These stat stackings will maximize your throughput, however it may seem that sometimes you heal for crazy amounts and then other times feel underpowered due the the rng of crit. Stacking Power gets you less throughput but your healing will feel more consistent and predictable.
So for pvp, it depends which "style" you'd want. Personally I always err on the side of throughput.