On April 14, the Washington state legislature passed SB 5171, which moves the primary for all office from late August to the first Tuesday in August. The deadline for candidates to file in that primary in 2012 (assuming the Governor signs the bill) will be May 18.
One of the disadvantages of top-two systems is that they close off all routes to the November ballot very early, because they do not provide any means for anyone to be on the November ballot unless that person has run in a primary. Thus, no one will be able to enter a Washington state partisan election beyond mid-May (except as a write-in candidate), almost six months before the election itself. Before 1977, Washington state had a route to the November ballot as late as mid-September.