User blog comment:VideoGameFan9012/Season 2's Upcoming Episodes/@comment-3094698-20120722190158/@comment-1038387-20120722193020

"characters should retain their origins from the comics"?

Characters with new origins:
 * Artemis
 * Beast Boy
 * Blockbuster
 * Blue Beetle
 * Clayface
 * Flash
 * Jay Garrick
 * Garth
 * Rumaan Harjavti
 * Impulse
 * Bernell Jones
 * Amber Joyce
 * Kid Flash
 * King Sha'ark
 * Klarion
 * Marie Logan
 * Mammoth
 * Match
 * Miss Martian
 * Mister Twister
 * Mr. Tawny
 * Neutron
 * Red Arrow
 * Ronal
 * Alan Scott
 * Amanda Spence
 * Hugo Strange

And this is a modest list, taking into account multiple retcons.