I'm extremely excited to learn that Mark Kleiman has been picked to lead Washington State's marijuana legalization efforts. I've known Kleiman slightly for years, and am a big fan of both his blogging and his books. He's one of the very best thinkers on crime control and drug policy out there and his work has very heavily shaped my views on the subject.
It remains to be seen what kind of mess the federal government manages to make out of Washington's policy changes in this regard. But hopefully they'll do as much as possible to but out and see what we can learn from a little federalism here. As Kleiman has often emphasized, the fact of the matter is that we know very little about the public health impact of making marijuana cheaply and conveniently available. One plausible story is that marijuana would substitute for alcohol use, and since marijuana has fewer health risks than booze that would militate in favor of policies designed to make pot at least as easy to get as beer. Another also possible story is that legal marijuana will complement drinking, and therefore exacerbate existing alcohol-related problems. That would indicate that we should try to make pot less widely available than beer currently is (though still more available than under the status quo) along with higher taxes on alcohol.
These are the kinds of issues that legalization in Washington and Colorado will let us explore, and it's great that the effort is going to be led by someone who's attuned to them and really interested in pragmatically seizing this opportunity to build a much better policy framework than the dysfunctional status quo.