1. It's a bad idea to stanch speech because you're afraid it will inspire terrorism. Note that this principle applies not just to Seth Rogen movies but to Senate reports on torture.
2. As Jeet Heer has pointed out, North Korea became one of Hollywood's go-to villains not just because it has a cruddy regime that any sensible person despises but because it seemed safe to offend it: "unlike China or [the] Islamic world it isn't a market for [the] globalized film industry." A few years ago, the studio bosses even made a last-minute change to the Red Dawn remake so the bad guys would be Korean rather than Chinese. With these threats, those days seem to be over. Not only is Sony burying The Interview, but New Regency has just cancelled an upcoming Steve Carell vehicle called Pyongyang.
3. That said, North Korea isn't necessarily behind the hack or the threats. American officials reportedly think it is, and those officials may well be right. But I won't be surprised if it turns out that a couple of kids from 4chan did the whole thing. When in doubt, pick the scenario that makes everyone involved look the most ridiculous.
4. In the meantime, more theaters should follow the example of the Alamo Drafthouse and show Team America instead.