What comes after letter Z?

alforque tweeted: WTF is Gen Z?! RT @ChicagoGirl1: There is a Generation Z now? When did this happen? http://bit.ly/ciOPp1

What would come after Generation Z? Is there a letter that comes after Z? In the Greek alphabet, the last letter is Omega. Would that then be Generation Omega?

A yelp post asks, If there was a new letter after "Z", what would it sound like? Here's a couple of their responses:
-- Gillooly
-- Sub-class 'z', 'zed'
-- A Double "Z" like "ZZ" like Double "U" makes a "W"
-- it would be the schwa sound we all learned about in phonics in the 1970s

Rather fitting that this Yelp post about the end of the alphabet has its comments turned off due to the post being older than two months. It's like the question about the endings, hit the end itself.