Today I finally passed Exam 70-553. I originally took both 70-553 and 70-554 as Beta Exams over a year ago. Since then I have been busy doing other things, but recently I have been ramping up again to try to actually pass them. That's why I had been posting some supplemental notes recently.
As far as preparation, besides the plethora of links you will find on this site, as an employee of Avanade, I had access to Transcender exams which were instrumental in preparing me this time around. I also spent much of Saturday at Barnes and Noble using the various study material they had. I was there so long I am surprised they didn't try to throw me out :)
The format was the same as the betas, three sections of thirty questions each. I didn't pass with much room to spare and really wish I studied more on App Domain Creation, Mobile Controls and Click Once Deployment. But in the end, I passed and that's all that counts.
I am aiming to take 70-554 at the end of the month or early June. One down, one to go.