In the near term, I doubt the Sprinter will have much affect positive or negative on home prices, unless the home is within a few hundred ft of the tracks in which case it will be negative.
In the long term, energy is going to get much more expensive and mass transit will become more and more important.With the Sprinter and connection to the Coaster, you can go all the way downtown on public transportation!
I would think that homes within walking distance of a Sprinter station will increase in value in the long run – whether that is 5 years or 20 years remains to be seen.