ArcGIS 10.2 was recently released. This has changed the method for activating a student edition of ArcGIS 10.1
Use the link above to pre-register your activation code for ArcGIS 10.1. If you use the link http://www.esri.com/StudentEdition you will see an error (error code 7174) during the activation process.
I should have codes valid for ArcGIS 10.2 in the very near future. Look for further updates here if you are interested.