Pros
It is a large firm in which there are many networking opportunities. Depending which team you are on and what sector you are in, the possibilities and growth are endless. The culture within Deloitte make this a place where information can shared easily and people are willing to help you. There are many different activities / clubs / organizations that one can become part of too. Giving back to the community is also well regarded. Depending what project you are on, what service industry line you are in and what you are specializing in, Deloitte can be a really nice place to work.
Cons
With the economy being the state it is in, Deloitte has really cracked down on the amount of training and internal job opportunities. For example, training is still encouraged if it is CBT based, but if you need to go out of town, be ready to write emails on why they think you should go. Also, the ability to transfer from one area to another is also on hold for the time beings (ex: Deloitte & Touche AERS to Deloitte Consulting). The hours are really long and people will have to learn to deal with it. Utilization is key. If you don't have the utilization, be prepared for some bad news.