HBLR is probably gonna go two ways once in SI, its either gonna go west, or go east to St George as you said. Now, I doubt the line would end up at St George, but there aren't any set plans or anything so it can would up anywhere. Hell, it can end up at Eltingville Transit Center or run down where the 122 use to run (I'm totally blank on the routing of the 122 in Staten Island right now). And no, I'm not talking about the 144, thats still around, and the S89 follows much of that route anyway.