I can't answer for Gary, but I can say  I have yet to see any of my non-wordpress Disqus comments in any of my various link profies.

Gary,

I'm doing the same thing you are.  If you have 100 disqus comments out there then are you seeing any of them showing up as backlinks to your site?  Right now I have probably half that amount from a lot of non wordpress websites and I have yet to see one of them linking back to my site.  I don't feel enough time has expired as some of these sites I'm sure it takes Google a while to crawl.  However, one in particular is an NFL site that I'm sure gets crawled several times a week.  None of those links are showing up.

If you aren't an SEOMoz Pro member go to Alexa or Majestic and run a link report to see if you are seeing your comments linking back.

I have just started using Disqus and looking for "on-topic" sites that use it.  None of my posts have been indexed on non-wordpress sites.  I did some research and found that Disqus uses Javascript to render the comments which googlebot won't be able to read.  However, it appears there are plugins in wordpress that renders the comments into HTML that can be seen when you view source.  Thats probably why you see your comments being indexed on wordpress sites and not the others.

I'm still testing this myself and would like to hear from others on this topic -good or bad.

I have just started using Disqus and looking for "on-topic" sites that use it.  None of my posts have been indexed on non-wordpress sites.  I did some research and found that Disqus uses Javascript to render the comments which googlebot won't be able to read.  However, it appears there are plugins in wordpress that renders the comments into HTML that can be seen when you view source.  Thats probably why you see your comments being indexed on wordpress sites and not the others.

I'm still testing this myself and would like to hear from others on this topic -good or bad.