Update:

After waiting a while longer, when I try to refresh the "try later" page it "loops" me back to the upgrade moodle page. (below)

Your Moodle files have been changed, and you are about to automatically upgrade your server to this version:

2.4.1+ (Build: 20130222) (2012120301.12)

Once you do this you can not go back again.

Please note that this process can take a long time.

Are you sure you want to upgrade this server to this version?