In my 2013 book, “Scrum – A Pocket Guide”, I describe two future challenges of Scrum.
The first challenge concerns the way the role of the Product Owner is fulfilled. We often see that representatives or proxies of product management are fulfilling the role. The benefits realized through Scrum would be higher if product managers would directly engage in Scrum, through the role of the Product Owner.
The second challenge is the improved understanding and adoption of Scrum by management, think about operational IT management, sales divisions, delivery managers, product departments and hierarchical CxO management.
I would add a third challenge, related to scaling. Many organizations have adopted Scrum and see the benefits at the scale of one or some teams. Organizations pursue the same benefits with many teams, but struggle in scaling Scrum while respecting the principles and foundations upon which Scrum are built.