Outlook 2007 isn't included in the home and student version of Office 2007.
Other than that, you can run a mix n'match of Office products on the same
computer.
I guess the subject was a typo then?
Yes, Outlook will continue to work as Outlook is not included in the Office
2007 Home and Student Edition, so you'll continue to use Outlook 2003. The
only thing that won't work is to set Word as the e-mail editor and some
other cross functionality between the Office applications.