Comment 30 for bug 27323

I agree that the UI is a separate issue. What I was wondering was whether hal had this capability already, and after doing a little digging, discovered that it indeed does, and is enabled by default in Ubuntu. For the benefit of anyone else reading this, I'll explain.
(This is from /usr/share/doc/hal/examples/no-cd-media-check.fdi)
All you have to do is create a new .fdi file in /etc/hal/fdi/policy/ like follows:

<?xml version="1.0" encoding="UTF-8"?> <!-- -*- SGML -*- -->
<deviceinfo version="0.2">
  <device>
    <match key="block.device" string="/dev/hdc">
      <merge key="info.addons" type="strlist"></merge>
    </match>
  </device>
</deviceinfo>

Just change the match "string" attribute to match the device you wish to blacklist from hal's polling. Restart hal and voilà!