The trick to using the \author and \title (and \date) variables is to
use them after they've been defined, but before the title page starts.
They don't get reset to \@empty until the titlepage is complete
(specifically until the \maketitle macro runs), so that's the magic time.
If you want to use them inside a stylesheet, your code must look like
this: (Note- When using the memoir class, this \marboth command adds the
\author to the header of even pages and the \title to the header of odd
pages)
\AtBeginDocument{\markboth{\@author}{\@title}}
The variables available to you are \@author, \@title, and \@date. As
stated earlier, you just have to use them during the proper moment. The
\AtBeginDocument macro for packages allows you to do just that.
I thought I should post the proper solution in case others come
searching for it at a later date.
-James