Gen Y is what they call Millennials now, same thing. Z would be the 9/11 babies, who aren't really defined at all yet since they won't start even hitting the voting booths, unemployment lines and college for a few years. I've heard several variations on Children of Terror, Homeland Security Babies etc for them. Also heard them called the iMarketedTo generation or iGeneration, since they weren't able to talk until iPods and iMacs were things.