Sadly i dont think the game going F2P will make any difference population wise
Last May when SOE gave 6 month Planetside sub to anyone who had ever played Planetside & PS2.......other then the first couple of days the game was dead
If anything i would make the most of it why you can
Unless a good amount of people actually start playing when it goes F2P...it wouldnt surprise me if they shut the game down all together