Len Downie has yet to formally step down as executive editor of the Washington Post, but the list of possible replacements is a mile long. Now, a source with intimate knowledge of the situation tells Radar that Newsweek editor Jon Meacham is one of the leading candidates to become Downie's successor.

It's unclear both when Downie will step aside—although we're told it will be by January 20th—and when an official announcement regarding his replacement will be made. Meacham, who has been with Newsweek since 1995, was named editor in 2006. Of course, his departure from the staid newsweekly would make available the top slot at the mag as well—a position which Radar hears Newsweek International editor Fareed Zakaria is actively pursuing.

Zakaria, whom is perhaps most recognizable in his capacity as the guy Jon Stewart taps to appear on the Daily Show when someone more famous cancels, is said to be touting the fact that circulation numbers of Newsweek International editions he oversees are up, in contrast to the declining numbers of the domestic edition.

Multiple efforts to get in touch with Zakaria were unsuccessful—depending on the day we called, he was either: doing an interview, out to lunch, at a Yale University board meeting, taping a television segment, in a meeting, or heading to a meeting. Says his assistant: "It's like this every day. The man is busy!" Perhaps a little too busy. Snips a Newsweek insider: "The guy seems more interested in being on TV than editing a magazine."

As for the possibility of Meacham replacing Downie, a source notes a major drawback: he's been characterized as the least people-friendly editor in Newsweek's history. In fact, staffers now think of Meacham's predecessor Mark Whitaker—never particularly warm and fuzzy himself—as a secular saint in comparison.