Washington Supreme Court briefs (June 2006-date) are now available on the Washington Courts website.
You can browse the briefs by case number, by case name, or by hearing date. Or you can search. I tried searching for "confrontation" and pulled up briefs discussing the confrontation clause.
The Courts site also has Division II briefs filed since June 2006.
A welcome development!
Update (Feb. 25): Welcome, that is, to researchers who have been frustrated working with microfiche briefs. Some lawyers, though, are not sure it's such a boon for their work to be available to anyone who wants to cut and paste.