The California Secretary of State’s web page has a tentative list of candidates for the June 3, 2014 primary for Congress and state office. The final list will be released March 27 and will probably have a handful of additional candidates listed, after disputes over the sufficiency of their petitions is resolved.
For the partisan offices, there are 560 candidates. When these same offices were up in 2010, under the semi-closed primary, there were 654 candidates (that 2010 total does not include the fourteen candidates who ran for U.S. Senate in 2010; there is no U.S. Senate election in California in 2014, so omitting U.S. Senate from the 2010 total makes the comparison fairer). It thus appears that California’s switch from a semi-closed primary to a top-two primary has caused a 14% drop in the number of candidates who filed to be on the ballot, when the two gubernatorial election years are compared with each other.
At the 2014 primary, there are 2 U.S. House races with only one candidate, 3 State Senate races with only one candidate, 14 Assembly races with only one candidate, and one State Board of Equalization district with only one candidate. In those twenty races, there are opportunities for candidates to file as write-in candidates in the June primary, and to have some chance of placing second and qualifying to be on the November ballot. In races like that with only one write-in candidate, obviously that write-in candidate will come in second and will be on the November ballot. But there are likely to be multiple write-in candidates in most of those races. Thanks to Jim Riley for the link.