Today Microsoft officially announced the name for the "service" we used to know as "Project Madeira". But Dynamics 365 isn't "just" Project Madeira. It's so much more.
As of today, we still only knows a little. Please join me in trying to answer all the question you might have.
I know for my case, then I still have a lot of questions.
You may know me, if you have been a member of Dynamics User Group before. If not, then I was once upon a time an actual userr of NAV. But I went back to college and learned to program and fell in love with Navision. That was in 1990. Since then I have been working as a NAV professional (development, consulting, training, systems architecture, project management) for both partners and end users. I became a Dynamics NAV MVP (Most Valuable Professional) in 2004, and have been reawarded every year since.
I do this because I love to help users and customers improve and optimize their business process. And I think that Dynamics 365 offers all companies, the same state of the art functionality that otherwise has been available only to large companies, with deep pockets for IT services.
I'm aware that this forum might be a bit quite yet, as Microsoft is not going to actually release Dynamics 365 until October 2016. But more about that later.