When Hiro is searching in Mr. Linderman's vault for the sword, it's listed as being in drawer CRM-114. "CRM 114" is an alphanumeric code used in many of the films of Stanley Kubrick. One of the films using that code was A Clockwork Orange (1971) (see trivia), which stars Malcolm McDowell - who also appears as Mr. Linderman in this series.
When Mohinder is talking to Sylar he mentions 4 genes that could be the key to it all. The Heroes Helix is half a strand of DNA with 3 genes on it.
The "Previously on Heroes" opener is in Japanese.