User blog comment:Rupert Giles/Layout Changes: Breakpoints and Typography/@comment-208566-20150519182632/@comment-126761-20150519183120

The update should not require significant changes, unless heavy CSS customizations have been used.

If content area changes are required, they very likely were already an issue for users on smaller devices. A significant reason for doing this change was to keep a more consistent layout across devices, to help avoid these kinds of issues in the future.