Heh, back in the year 2000 when I had found my first online simulator European Air War (it was the time of Roger Wilco) and had played it for a few weeks, I woke up in the middle of the night, shouting: "Testing, testing, can you hear me!" My wife still reminds me every now and then about it.
Subs in AH would indeed bring a new level of game play - if supply ships etc played more important roles that is.