In addition to all the great suggestions above I would like to add the following:

• Secunia keeps things simple by listing items by Program name. I think that is far superior to Sumo's approach which overly complicates matters by listing individual files.
  • Some of the files Sumo discovers are drivers. While having VulnDetect discover drivers might be nice in the future, I think a focus on programs in the near term should be the priority
• Secunia includes both an Installed version number and (if different), a Secure version number of each program. The latter is useful for when I need to find the update myself.
• The size of the database of programs VulnDetect can discover will be very important. PatchMyPC's database is far too small to be of any value to me. Secunia detects ~60 items of importance to me (excluding the 32 bit duplicates), whereas PatchMyPC only covers 20.