> Is there a problem with using Numpy 1.5 and the enthought libraries? What things will break if I upgrade?
All the enthought libraries will work fine with NumPy 1.5 if they are compiled against that version of the NumPy API.
The libraries that need the NumPy C-API inside of the current release of EPD are compiled against NumPy 1.4. As a result, any of these binaries has the strong possibility of not working correctly (or at all) with a different binary version of NumPy (like NumPy 1.5).
So, depending on what you mean by "the enthought libraries", your answer will vary.
I know for sure that enable (Chaco) depends on the NumPy C-API. I don't think other libraries use it, but I don't recall.