According to John Perrotto of Baseball Prospectus:
The Nationals, according to multiple industry sources, are strongly considering firing general manager Jim Bowden and replacing him with Blue Jays assistant GM Tony LaCava.
This rumor first surfaced on Ed Chigliak's Federal Baseball blog yesterday. Fire Jim Bowden rounded up a bunch of info on LaCava. I've heard the Nationals may also consider in-house candidates such as Deric Ladnier and Mike Rizzo.