this episode was more about trust than anything else, from what I can tell.

Nathan and Peter trusting eachother as brothers (this has been an ongoing theme)
Daphne trying to understand why Parkman trusts her
HRG regaining the trust of his daughter Claire
Sylar trying to earn the trust of his father Arthur
Elle trying to learn if she can trust Sylar

Previously I think we saw Hiro regain the trust of Ando (and visa versa)