Kaito Nakamura (Hiro's father) likely has some power. I think his power is immortality. Here's why:
- In Landslide, he mentions to Hiro that he's been waiting for generations for some spirit/power to manifest, and didn't think it was in Hiro, but now he sees that it is. Has his family been waiting this long, or has Kaito himself been waiting?
- In the preview for Season 2, Hiro sees a samurai warrior on a horse. It looks like George Takei's eyes in there. It is just family resemblance, or is it Kaito himself in there?
Immortality is also time-related, so maybe there's a time theme to the powers in that family.
Another power I'm waiting for is the ability to see alternative futures. Linderman somehow knew that he needed to get Niki and DL together so that he could use Micah's power to help Nathan win the election. If Niki and DL hadn't gotten together, even Isaac's power wouldn't have predicted that Micah would be born or that he would have the power he does. I think we need a different sort of foretelling power than what Isaac has; it's possible Kaito has this. My top choice for Kaito's power though is still immortality.
Update: [2007-09-30] Given the events of Four Months Later, both in revealing Kensei, and in the events on top of the Duveaux Building, it seems unlikely that Kaito is immortal.
Update: [2007-11-09] My original theory was that Kaito was Kensei, and immortal, but although Kaito is not Kensei, it looks like Kensei is indeed immortal. And he's probably trying to destroy the world in an attempt to put his broken hearted self out of his misery.