Under current law, a development project "vests" when the developers applies for permits, meaning any changes in land-use regulations do not affect the project. In effect, Washington's vesting rule freezes land-use regulations in time, and local governments may not require the development to comply with new land-use laws. But that rule may change:
Introduced by Sen. Adam Kline, (D-Seattle) (D) on January 15, 2009, to change the Washington state vesting laws so that a project is vested at the time of approval of application, not submittal. This would mean that an application is review and approved based on new rules and regulations, even if the new rules and regulations were approved after the submittal of the application.
Source: Washington Votes email update.
It'll be interesting to see if Sen. Kline's efforts go anywhere.