Quick A: Because exceptions occur (or not) dynamically.

Why is C++0x's noexcept checked dynamically?

I am curious about the rationale behind noexcept in the C++0x FCD. throw(X) was [deprecated], but noexcept seems to do the same thing. Is there a reason that noexcept isn't checked at compile time? It seems that it would be better if these functions were checked statically that they only dcalled throwing functions within a try block.