I am heavily bored to tears with ww2 (I start yawning at the thought of it lol). ww1 is a fresh start and despite some teething problems still holds my kindrid interest and in my case at least, continues the subscription.
I would totally love a Korean war arena and think HTC should definately pursue it. Unlike some, my approach to air combat history is not narrowly defined by a single era (or worse, a single plane type). The entire history of it is what intrigues me.