Mine was about a flavouring company called Sugar and Spice. It's been recently acquired by another company and is going through some trouble. My advice is not to spend too much time on the first page, as it was talking about the different divisions, locations of factories and the organisation setup which really didn't have anything to add to the overall solution. I finished exactly on time, and my advice is to read the questions first, then read the case as it will help you understand what pieces to concentrate on...overall I'd say it was easy compared to the strategy house case studies.
You are asked to present your analysis to a senior partner on 4 slides, and my approach was using the current state vs. future state. The interviewer will ask a few questions about your reasoning, and it's important to project confidence and be sure of your answers (regardless if you are 100% sure of them or not) after all they don't want you to be a complete mess in front of a client. He will ask you something around 4-6 questions then move into a few generic questions like "If I phoned your boss what 3 strengths and 3 weaknesses would he tell me about you?" my advice is just be yourself. Spend some time reading about Deloitte, but don't rehearse competency-based questions/examples, it won't sound genuine.
You are asked to summarise a slide pack into a 2-page report which your line manager will use for communication purposes with regional managers for that company. The project talks about an ERP implementation that was done in the USA and now will be implemented in Europe, so your task is to summarise the slide pack from the stakeholder review, to bring the EU regional managers upto speed with what's been done in the US, and what's about to come their way. It's important for you to communication the FACTS, not your personal opinions. Also, there's a trick that a few people didn't see where there's a possibility of lay-offs due to improved effeciencies of the new ERP system. It goes without saying that you shouldn't mention this in the report. Also sell Deloitte and their expertise in running similar projects, and how you're excited to help the EU branches achieve their goals...and all that crap.
Note: HR told us they'll let us know within 2 weeks, mine took 16 days and I got it. Feedback was strong on all sections of the AC - now waiting on their offer.
Best of luck and if you have any questions let me know.