Top of the mind thoughts:
1. Provide long term vision on where the IT department will fit in the overall value chain of the organization and how agility can help it in achieving that goal
2. If the long term intent is to go agile for majority of projects, create a transition backlog
3. Prioritize and reprioritize often
4. Inspect & adapt as you go along the journey
5. Lead by example, follow agile principles
6. Encourage & reward successes and support learning from failures

Thought of penning down some of the issues I see with the projects where agile is tried via feeble mandate (lets just try it – top-down) rather than as a joint initiative between management and teams. The list will grow over time:

# communication
–>> Email being the preferred mode of communication rather than face to face communication
–>> Unwillingness to see the bigger picture by staying within the zone of “defined” responsibility
–>> Lack of communication on why we’re doing it and how we want to do it
–>> Lack of training & coaching

# initiative
–>> Unwillingness to try something different
–>> Unwillingness to understand new ways of working
–>> This is how we work, this is common sense, this is the only way it is practical!
–>> We will not touch the Engineering practices

# openness
–>> Unwillingness to share progress, impediments
–>> View that Agile is just an “iterative” waterfall
–>> Buffer resources for some reason, not made visible to customer

# collaboration
–>> Handling the fixed price contracts with variable scope is difficult
–>> Will not start the work till the SOW is signed/cost & scope are cast in stone
–>> Someone needs to prove that Agile will not cost more than what we are used to