I do not personally believe this will end with Donald Trump being impeached. I suspect the most likely outcome is a lot of smoke and limited fire, with a handful of mid-level personnel, maybe including Manafort, getting nailed on perjury or obstruction charges and ultimately pardoned. Of course, this does not mean the ongoing investigation has no value: establishing a historical record is important.
If you ask me, I would say there's about a 20% chance Trump will run again and win, a 30% chance he'll run again and lose, maybe a 10% chance he'll declare again but lose in the primaries or drop out because he's going to lose, maybe a 25% chance he'll not run again, a maybe a 10% chance he'll resign early, and a 5% chance that he will die during his current term. So I would place impeachment as a subset of that 10% chance.