If you know that it's doing lag compensation you can use it to your advantage in tight spaces by starting to shoot before your view is around an edge. And CONTINUE to shoot when someone moves even if it appears he is moving behind cover.
Well, that is obviously a bad thing but you make it sound like this is something terrible, when you can negate the effect more or less.
Also they did already announce those 3 expansions so I do not expect this to change. Even if sales for this DLC should be grand indeed.