Confused about tracking git master

Hi,

I'm tracking git and somehow getting confused about how to get
updates.

To start, I did: git clone git://git.kernel.org/pub/scm/git/git.git

To get updates, I _think_ all I have to do is 'git pull'.  Doing so I
get:

    Unpacking 157 objects
     100% (157/157) done
    * refs/heads/todo: same as branch 'todo' of git://git.kernel.org/pub/scm/git/git
    * refs/heads/maint: same as branch 'maint' of git://git.kernel.org/pub/scm/git/git
    * refs/heads/origin: same as branch 'master' of git://git.kernel.org/pub/scm/git/git
    * refs/heads/pu: does not fast forward to branch 'pu' of git://git.kernel.org/pub/scm/git/git;
      not updating.       

Then when I do git whatchanged, the last change is on Saturday the
15th.  I'm figuring there has probably been at least one commit since
then?  So I tried 'git checkout origin' and then repeated the
whatchanged call and see:

    diff-tree 2855d58... (from bb99661...)
    Author: Junio C Hamano [off-list ref]
    Date:   Mon Apr 17 17:46:07 2006 -0700   

Is there a step I'm missing?  Or am I just misunderstanding what to
expect?  Clarification on either of those would be appreciated.

Thanks,

+ seth