I just passed the 10,500km mark (mostly touring and twisties, some commuting), and my front tire has plenty left. My rear, however, is nearly down to the center wear bead... I'd estimate that the traction grooves will be flush with the bead in about 400km... My plan is to ride it out for this season, garage the bike for the winter, and then replace it first thing next season with an oil change and fluids check/inspection. Not sure what tire I'll get at that time, but this tire should last until then.
-Dave