Anyone else think the helicopter Rick saw might be a tip of the hat to the original Dawn of the Dead?
In a way, yes; however, in the comic series, our gang did witness a helicopter land (but that event and subsequent events related to it took place some time in the future from where we are at now in the TV series). So they might follow up on the helicopter in Season 2.
Or...this might be what inspired the trip to the CDC, the idea that Rick might have thought the chopper was heading there. Clearly it was going somewhere.