After studying for the past few months I took the Microsoft .NET Framework 3.5, ASP.NET Application Development exam today and passed with a score of 873.
This is certainly the broadest certification exam I’ve taken so far. I almost spent the entire allotted two and a half hours on the test.
I'm now MCTS .NET Framework 3.5, ASP.NET Applications. This is really cool considering that as at today there are only about 271 certified people worldwide. 
I guess everyone else is waiting for the training kit to be released in April next year.
If you can't wait till April, here's how I studied:
Prerequisites:
Study Plan:
- If you are not comfortable with ASP.NET AJAX, read Introducing Microsoft ASP.NET AJAX
by Dino Esposito.
- Read Programming Microsoft ASP.NET 3.5
, also by Dino Esposito. This is a very detailed book on ASP.NET. It covers a broad and practical range of ASP.NET topics.
- Get a copy of MCTS Self-Paced Training Kit (Exam 70-528)
. This is the training kit for the .NET 2.0 version of this exam. You’ll need it to study topics not covered in the books I mentioned earlier.
- Study Chapters 4, 5, 10, 12 and 13.
- Practice the “Practice tests” on the CD that comes with this kit especially questions from the mentioned chapters.
- Purchase and practice the Measure-up practice tests, available at http://www.measureup.com/catalog/exam.aspx?vid=5&cid=MCTS&tid=139 . I cannot over-emphasize this step. It is important that you score a 100% twice on ALL the questions before attempting this exam. Do not take the exam if you have not seen and understood all questions and answers in the Measure-up practice tests. It’s a great indicator of your preparedness level.
- Take a look at the 70-562 Preparation Guide and if there is any topic you do not instantly recognize, look it up in MSDN and learn it.
Tips:
- Practice every topic from each book you study.
- If there is anything you do not understand, Google it and master it.
- Pay particular attention to features that are new with ASP.NET 3.5 such as the Listview control, IIS 7, WCF, Aspnet_merge.exe, Datapager control, etc.
- Practice a lot of web.config configuration settings and command line tools like Aspnet_Compiler.exe, Aspnet_regiis.exe, etc.
Do not under-estimate this exam; it is difficult because it covers a very wide range of topics. The exam basically tests your ASP.NET 3.5 experience-level.
However, by the time you study and practice all the topics I’ve mentioned, you’ll be quite experienced.
Good luck!!