Now that fashion go one week trip to U.S. from Europe by the gain Euro / Dollar is interesting to note the announcement by the U.S. Transport Agency on laptops.
At least in Europe and my experience is not necessary to remove the laptop from its case, but as there are many types there are different cases that they can be used and others not, you'll have to get the laptop.

There are only three types accepted a call butterfly, one triple and cover ordinary laptop that only has room for the laptop itself. They have even published a short guide to manufacturers who warns that use and is not used in the manufacture of such bags.