MicrosoftI was looking at the FAQ and was severely disappointed to see that "How do I switch the view back to how it was before?" was not an option.
Messing with UI is no small feat and should be done with care. A lot of users will notice, be bugged shortly and then move on and adapt to this new interface.
Users spending most of their day in Outlook however will feel the frustration of their muscle memory moving the cursor down to that lower left corner 100+ times a day for the first month of this introduction.
Obviously its your product to do with as you feel, but be aware that unless you solve UI-related problems requested by the community, users prefer nothing to change in a UI of a piece of software they have been using for decades.
This is a bit like flipping the head of a hammer 90° and putting it back in the carpenters toolbox and expect him to be fine with it.
