Jonathan Molot (civil procedure, professional responsibility, federal courts, and administrative law) at George Washington University Law School has accepted a tenured offer from the law faculty at Georgetown University.
Here's a question: has a GW faculty member ever turned down an offer from Georgetown? (Let me know, and I'll add an update.) Georgetown, it seems, often plunders the GW faculty (just in recent years: John Thomas in intellectual property and William Bratton in corporate). I can't think of two essentially "national" law schools in the same city that stand in such a relationship: Columbia used to enjoy such a position vis-a-vis NYU, but that is now ancient history; UCLA and USC have been basically peers for a very long time, with little movement between them. University of Chicago and Northwestern may be in a similar situation (though recently some faculty have retired from Chicago and taken up posts from Northwestern, but in general, to the extent Chicago has wanted to hire Northwestern faculty, it seems able to do so). Stanford has often succeeded in hiring Berkeley faculty, though they aren't as closely situated as any of the others.
UPDATE: A GW faculty member points out to me that since Georgetown only hires faculty after they have visitied, any GW faculty not interested in Georgetown would simply not visit in the first place.