Yesterday I tried myself in the 70-446 exam and I succeeded! 
It wasn't easy, wasn't fast and wasn't even relaxing 
but I liked it!
I began it at 8 o'clock and finished it at noon and in the meantime I took only a short toilet-brake 
But I think everyone is more interested in the exam not my personal things 
So the structure is completely different than in 70-445. There are 8 case studies (don't forget to count while taking the exam just to know how much is left I forgot it and after the 5th I thought section-by-section that this was the last) with 4-8 questions. That seems quite a few and it is.
Most of my exam time was spent with reading and comprehending the case studies. You have to do it very carefully to see the coherences. Though many aspect of the studies was not covered by the questions in that specific exam there could be many others.
My personal opinion is that it is a good exam. The first 2 hours was pleasant like playing a strategy game or like solving a logical puzzle but the remaining half became more and more tiring. The questions were good as well I mean they were focused on the important aspects and not on the technical nuances. If you have worked with the SQL Server BI suit in practice and were involved in the designing as well this exam would not be a problem. I encourage everyone to try it after 445!
And it's a good feeling being an MCITP 
Currently there are 1386 BI MCITPs worldwide and that's not a big(int) number