Hmm, I was contemplating going a commando/medic as my trooper spec, but according to this, it wouldn't really be viable except as extreme backup heals, in which case I may as well just go DPS and not worry unless in certain situations. I will have to test it out when the game launches and get a better first hand idea.
On the other hand, healing with a SI/Sorc was pretty pleasing for only having two direct heals and a shield. It was tough at times, but worked. I can't wait till I can become invested in a character that isn't going to be unplayable at the end of a weekend, so I can try out builds.