How can I view the items in the Spotlight cache? I'd like to view the data spotlight has imported.  Is this possible?  

EDIT:  For example I can do this:

mdutil -svvv /Volumes/h8rdrive


and find out this volume was indexed.  

I'd kind of like to find out what's not indexed though.
mdfind is your friend here.

If you simply wanted a list of every file in your spotlight index you could do:

mdfind /


You can also get it to provide a count of the files.

mdfind -count /


On my system this returns 224353 which is a good reason not to run the first command!