I'm currently enrolled at WGU (school of business) and absolutely love the convenience and flexibility! It's simply wonderful to be free of the tyranny of professors, cohorts, and seat-time! However, as Helen has said, this is a completely different model and it is certainly not for everyone! [Anyone who has the slightest aversion to a LOT of reading and a LOT of writing would be well advised to keep moving ;-) WGU is not for you.]
That said, if you haven't do so already, go back to the website and print out the 11 page PDF file 'program guide for the MA in ELL.' This will give you the best summary of the program - the competencies you'll take, a suggested sequence, and equivalent credit hours. Note that each competency will have a study plan similar to the traditional syllabus listing in detail the readings and assignments to prepare for the actual assessment. The study plan for an objective assessment will be oriented toward the summative proctored exam, very much like the traditional, multiple-choice final exam to demonstrate you have the required facts and knowledge, the performance assessments are oriented around a step-by-step sequence of tasks to demonstrate that you have developed the necessary skills. Actually, I think these performance assessements are the ones that are going to challenge you the most and be the most rewarding since they tend to take on real-world examples and simulations. For example, you may be tasked with a reflective essay, a report, developing lesson plans or a multimedia presentation of a series of instruction modules.
http://www.wgu.edu/wgu/program_infor.asp?progID=349
As a working professional, you'll appreciate the variety of learning resources. It's not just the textbook and e-reserves anymore ;-) There are plenty of resources freely accessible online, others that are password protected, multimedia CDs, even online courses.
Initially, everyone has to take EWOB (Education without boundaries) - the WGU model, policies and procedures, the tools and resources you'll use, the software and skills you'll use, etc. In my opinion, this really is one of the keys to success as a student at WGU, the other is establishing rapport and working with your mentor.