I don't know much about if the game is really loosing many players or not, but I do know that my server has gotten so much smaller since I originally started playing on it, at least on imperial side.
First off the fleet, which usually had at least 50 people (around 100 daily originally) has gone down to 10-30 pretty much all day. The starter planets which originally had like 80-120 people have gone down to 20-30 on them (Dromund Kaas, Hutta, ect). The in between planets, from like Balmorra to Corellia have gone down from the already pathetic 15 on each planet to around 10, some from 10 to 5 or lower. One side usually dominates PVP, tends to be Republic on my server, probably from population decline on Imperial side.
I'm honestly considering quitting if no way to transfer to a bigger server comes soon. Server transfers should have been possible from the beginning, and server merges are starting to seem like a really good idea. I really enjoy the game and all, but if there aren't people to play it with, my 15 a month seems wasted.