I can say that we have 19 major worlds," he said during a Q&A session. "Then we have an indeterminate number of minor worlds. And our goal, obviously this being an online game, that we're hoping is going to last for decades, we're going to be, obviously, adding more to the galaxy map as the game progresses. We want to add dozens of worlds. Hundreds of worlds eventually. In 2025, we'll hopefully have 500 worlds."
This quote was from an interview back in June with one of the Senior Creative Producers in a Toms Hardware article. I had no clue that they had that kind of galactic scope in mind! Plus, a 15 year timetable!!!