This article from the Santa Clarita Valley Signal has some interesting details about the process taking place on the way to final designation of their new Enterprise Zone. All the way at the end, for example, the article notes that:
Laura Biery, administrative analyst for the city of Santa Clarita, said the Santa Clarita City Council is expected to vote on aspects of the Enterprise Zone program at its meeting Feb. 28.
That indicates that we should not expect that final designation announcement from HCD until some time in March. The article also notes that, once approved, the zone will be effective retroactively to 1/1/2011.