Is anyone actually dead? I've gone back and watched those episodes again, but it does not say that the people in the show actually died. Unless its losing something in translation this is what I am seeing.
Haruhi's siblings were killed in front of her, but we're not told if the robbers killed her. And she points out suicides prevent you from entering this world.
Iwasawa has a stroke and loses the ability to sing. Since that was her "life", this would be the end of it.
Takamatsu gets drugs after the baseball game. However since this would be suicide if he died from an overdose he should not be in this world.
Ayato's reason to live died with his father.
In each case there is no clear cause of death. Even in Iwasawa's case which is the only one we know for sure the cause of her injury, waking up after the surgery to relieve brain swelling caused by a contusion is usually a good sign.
Haha, someone believes the same conspiracy theories I do:
Well, maybe "believes" is a bit strong word, but still. Yeah, I had similar feelings, but have they since subsided a bit. Still, it would make sense. Also, some nitpicking - Yuri said herself she died later, Hinata supposedly got hit by a car(and even if he overdosed, no, drug overdose is NOT automatically a suicide, unless it's specifically intended as a means of killing oneself)
But no matter what it is, I expect a major twist, rather sooner then later - it's obvious that something needs to happen now, unless they were rushing this so much for no reason.