I have 2 level 50 character, both who got there in the past month thanks to the 2x xp weekends.
On my assassin I have 4 pieces of gear I've got from flashpoints (chest, legs, earpiece, and helm) and one (offhand) that I've bought with commendations.
As I see it the current best way for the level 50 character to gear up is to run hard mode flashpoints over and over for the new drops, it's especially good if you are a tank. Then use commendations to fill in pieces. The flashpoint gear has similar stats to the commendation gear, but lacks any set bonus.