I think the DVC resorts that have room service are only the one's that are connected to a regular WDW resort. These being BCV's,VWL and BWV's -- OKW has pizza delivery only. Not sure what will be over at SSR.
Not sure about SSR, but I order Room Service for breakfast at least once a trip at BCV. It is sooo good. I love that they come in and put a nice table cloth on th table and arrange the food.
Info printed in the Member Clubhouse indicated Room Service would be offered at SSR, but did not elaborate. I suspect the menu will be select offerings from the food court, which does serve meals all day long.