Some government officials, noting that Wilson's wife, Valerie Plame, is a CIA official who monitors the proliferation of weapons of mass destruction, intimate that she was involved in his being dispatched Niger to investigate reports that Saddam Hussein's government had sought to purchase large quantities of uranium ore, sometimes referred to as yellow cake, for the purposes of building nuclear devices.
The Time article is dated July 16. Corn says that the Novak article appeared July 14 (although I haven't looked up the article myself). So, as far as I can tell, it still looks like Novak is the first published source.
Thanks for the link to the Time article though; I hadn't seen it.