According to the Seattle Times ("Legislature has the votes"):
It is widely expected that the same heterosexual supremacists who forced a referendum in 2009 on Washington's comprehensive domestic partnership bill ( which they lost!) will do so again when Governor Gregoire signs the marriage equality bill into law.
The legislative majority correctly is refusing to include a ballot measure provision in the legislation because marriage equality is a civil right and they are supporting the principle that the rights of a minority should not be decided by a majority vote.
In other exciting marriage news, the Democratic Governor of Maryland, Martin O'Malley is expected to introduce a marriage equality bill today.
Hat/tip to Joe.My.God.