The general rule is that if you mention you have two laptops, then the officer will get you a bin to put one of them in. On a handful of occasions I've been told it's not necessary (I explain I've been told that it makes the image unclear before - once the officer was insistent I leave both in the bag, at which point my bag was set aside from the x-ray for hand inspection for an unclear image). Some TSA officers offer it proactively.

It depends on the airport - some TSA officers are better trained/stricter than others. (I've never had a problem with my Surface Pro 3 at any airport except MLI, they say that the Surface Pro battery looks like that of a regular laptop and not a tablet).