AGILE METHODS

I have started many agile engagements and I always get asked where is your project plan? Can you tell me the project milestones and target dates? Now, mind you this is before I have anything resembling a backlog or attended any kind of discovery workshops with the customer and core team members. I try to explain that while we have a Statement Of Work (SOW), it is high level and purposely vague and it will take some time before we understand the requirements and have a backlog. This means whatever plan I have produced is subject to change, in fact it will change.