I spent a bit of time helping somebody on freenode's #drupal-support IRC channel add teaser text to Ubercart's product grid view.
Here's an example of this from a site developed by left-click:
http://www.biolateral.com/catalog/biolateral-cds
It also includes audio, which also usually isn't in the grid display. I've removed that part from the code below to simplify things.
Awhile ago I posted a patch to add a checkbox to Ubercart to allow for this functionality. People seem to like it:
http://www.ubercart.org/contrib/5395
However, that patch modifies core Ubercart, which isn't ideal. Each time you upgrade Ubercart, you'll have to remember to reapply my patch. A better solution is to add a theme override to your theme's template.php file. This is a common practice in Drupal, so if you haven't done it before, now's a good time to learn. Just make sure you're ready to dig into a bit of php.