To get the MCAD, you can specialize in the area of interest to you, web or win.
Looking further out into the future, the MCSD certification (if I make it that far), I would need only two other exams. 70-316 is where I could pick up win for C#, and then the required 70-300 exam. All other requirements or electives for the MCSD would already have been met with my work above on the MCAD.
I am focusing on C# because the projects that I inherited were/are being done in that language, a decision made before my involvement by higher ups. I realize there are many ways in which to combine the exams, and I think it is great that MS has laid out a format which allows you to focus in on the area of your interest for the certification.