Are they the right features?
It's like that idea of doing the thing right, versus doing the right thing.
The mechanism in scrum is to ask a product owner what to do next. Not much seems to be written about how the Product Owner goeas about this task.
For complex enterprises facing complex problems I expect some deep thinking has to happen first.
Requirements may trickle into the tech team, but a big picture - maybe a business architecture - view needs to be established.
And then there is the change management aspect to consider. Training, getting people to adopt the change, scheduling other changes among system releases etc can also be a complex activity.
Picture CC, by darkmatter@ Flickr