We'll go many years with basically no additional information on where it's headed.

It's a completely controlled deflection method.

Because of this low gravity, we B612'ers talk about 'docking with' a near Earth object and not 'landing on' one.

That (will be) an impossible task, I'll tell you right now.

It would have devastating consequences if it hit. There is the serious question of whether, if it is headed toward impact, we will know enough to make a timely decision.

The danger is being overly optimistic about how long it takes to do that.