A few of my theories from the new season:
I think the most obvious is that Hiro actually takes the role of his boyhood Hero (Kinse?) to 'right' history, and becomes the legend his Father told stories about, falls in love with the girl, etc., etc.
I think the the writers are trying hard to make us think that the assassin who's leaving the 'death card' for all the 'Elders' is Nathan...the dude in the Belichick hoodie...a vengfull Nathan, going around serving his own form of justice to those who set the plan that took his brother from him.
He bumped into Hiro's friend in the very beginning of the episode as he brought Hiro's Father the newspaper (in which he found the death card). He came in the apartment after his mother was already there, then kicked her out, at which point she found her card in the hall.
Hiro's Father is pushed off the top of the apartment and dies from the fall...but there's no assassin laying next to him. So he either is a really quick healer and got up and ran away, or he never hit the ground and flew away (i.e Nathan).
So, not that it absolutely is Nathan...maybe someone else with the power of flight...we already know there are plenty of others who can fly (Peter, the new kid at Claire's school). Or maybe someone even shape-shifting to appear to be Nathan, as Sylar did in the alternate future before the bomb was stopped. Or even if it is Nathan, someone could be controling / persuading him in some way.
In any case, I just believe that is what initial direction it's taking...wanting us to believe Nathan is on some vigilante rampage.
Obviously Sylar is still alive...likely retrieved by The Company to attempt to put him to their use (as Midas man eluded to). I half believe that Linderman is probably still alive. We'll see.
I can't wait to find out who "the boogie" man is...could it be the English Kinse? Did the end of the show / preview of next week have Hiro talking to him about how he has powers like him? I kind of just caught a super quick flash of something...not exactly sure if I heard what I thought I heard. But that is the symbol from the sword everyone is so afraid of, isn't it? Same one around Peter's neck?
Is Evil Kinse traveling through time, taking his small-time, ancient Japanese pilage & plunder show to levels spanning time & history...setting up a clash of Hiro Kinse verses Boogie Man / Evil Kinse?
Just a shit-load of my thoughts after Episode One of the new season...don't know if I'm even close on any, but I think they all sound reasonable at this point.
LOVE this show!