I won't say the game is dead, but on my server there is definitely less activity after Tuesday to Thursday since most people sign on to mainly to do their SCOB T6-9 clears for the week, ST Loot, and cap out their soldiery. It's pretty quiet by Friday to Monday.

I can assume the game will be heavily populated once 2.4 hits for awhile with the population dwindling as people clear the content and cap out Ninja level.