The 1299 wasn't a "face lift". It is a different motor, different electronics, addition of the IMU, Cornering ABS, and other rider aids and other small things like different footpegs, different bodywork, etc.
No, it isnt quite as different as the 1199 was to the 1198, but it is a new bike. Therefore, i dont see Ducati coming out with another new one anytime soon. I would be willing to bet we don't see a different Superbike model (replacement for the 1299) till 2018.
Lack luster results in racing?
Since it came out the Panigale has been dominant in World Superstock (which is a true measure of the bike's natural abilities because they are raced in almost stock condition). And the Panigale has been on the Podium in almost every race in World Superbike this year...and that is without their main #1 rider being there most of the year due to injuries.
I don't see Ducati going away from their "bread and butter" Twin. But if they do, it will likely be a V4.