You can watch the signing here. The legislative success was the result, as in New York, of persuading a handful of Republicans and almost all Democratic state legislators to support marriage for same-sex couples.
It’s considered very likely that gay-marriage opponents will force a popular vote on this issue this November. Same-sex couples won’t be able to marry until and unless that initiative is voted down. Washington voters rejected an attempt to ban legal rights for gay families a couple of years ago, but “marriage” will be a tougher slog.
UPDATE: In case you missed it, you can watch the signing speech here. It is powerful.