Whatever it is, you might get asked things along the following lines:
What strengths and skills do you feel you have which make you suitable for the job?
Having read the job description, what do you think would present the greatest challenge?
What personal development needs do you think you have?
Where do you see yourself in 5 years' time?
What do you know about our organisation?
Keep reading the job description and if the company's got a website, try and learn a couple of things about the organisation that you can throw into the conversation - always impressive if you can show you've done your homework!