Only a few days after the Iowan state supreme court found legal limits on marriage to heterosexual couples unconstitutional, the Vermont state congress overrode the state's governor, Jim Douglas, to legalize same-sex marriage.  See the full story here: http://www.365gay.com/news/gay-marriage-legal-in-vermont/

This now brings the total count to Vermont, Iowa, Connecticut, and Massachusetts.  Of course, bills are being considered elsewhere, including New Hampshire and Maine, and the constitutionality of Prop 8 is being challenged in courts currently in California.  We're beginning to see progress for the "Six by Twelve" campaign for marriage equality in the New England region (a goal set for 2012).  Woo hoo!

Update (1:15pm EST): As of today, Washington, DC recognizes same-gender marriages from other states.  See here for the full story: http://www.washingtonpost.com/wp-dyn/content/article/2009/04/07/AR2009040702200.html?hpid=topnews