How can I map the "Archived" folder to "All Mail"?
For some reason stackexchange isn't letting me comment on the approved answer.

In any case, jtbandes' comment is incomplete, you have to set the custom app shortcut as:

"Message>Move To>All Mail"

Note the lack of spaces between the words. This is critical; it won't work otherwise. Simply typing "All Mail" will trigger multiple, redundantly named menu items with the keyboard shortcut. 

I've assigned mine to Command-Y to approximate the Gmail shortcut.

I learned this from a comment by LaraCroft_NYC at https://discussions.apple.com/thread/2572960?start=0&amp;tstart=0