How long has this been in development? It seems like NBC is only giving it another shot because of the success of Arrow on the CW. Like stated before "Superheroes are cool again."
I'm sure the success of Arrow has nothing to do with this. Arrow has done very well for the CW under CW standards, and the genre crowd has been very pleased with it, but its really not that crazy of a breakout or ratings hit in general.
It sounds to me like NBC is taking its cue from a couple of things happening in network tv right now. 1) Networks in general and NBC in particular have been relying heavily on known properties with pre-built in audiences to try to jump start successful shows; see Knight Rider, Bionic Woman, Friday Night Lights, Parenthood, About a Boy, Hannibal. Plus there are like 3 different Wizard of Oz related programs in development for nextr season. 2) Fox took that to a new level by bringing back 24 for an "event" series this May, which by all accounts is going to have all the success that NBC is hoping Heroes will have. 3) Fox has changed the game a bit this fall when it somewhat ditched the tv pilot process and instead greenlit a number of shows directly to series for the following tv season, and thereby pushing up the start time for the normal seasonal development/announcement period. NBC has seamingly responded by planning some direct to series developments already for the 2015/16 season.