User blog comment:Commdor/Game Informer ME3 Preview (Feb. 2012)/@comment-3053284-20120110110727/@comment-1388547-20120111060811

Agreed, it's not super-original, but Liara did foreshadow it in conversation at the Shadow Broker base after the end of LotSB. And obviously the weapon won't be the whole story, if we have rally the galaxy behind us to fight the war.