Yes. The Gold Line extension is going to have a huge impact on the SGV.
I don't live in the SGV, but the impact of the Gold Line on the Chinatown-Highland Park-Pasadena corridor [which it reached years ago, before the recently-completed extension] has been very significant, including lots of denser housing within Pasadena and sharp increases in house prices along Figueroa parallel to the Gold Line. I expect the extension to have an even greater impact over time.