Coming up today in the D.C. region:

Same-sex marriage: Washington National Cathedral officials are expected to announce that the cathedral will begin hosting same-sex weddings.

Corcoran Uncorked: The museum holds a new after-hours event, staying open for free from 5 to 9 p.m. and offering docent-led tours.

1600 Penn: President Obama will host the cast and crew of the new NBC series about a dysfunctional first family for a screening at the White House.

RGIII: Debate will continue over the decisions that led to the latest knee injury for Redskins quarterback phenom Robert Griffin III, who is slated to have surgery within days.