this is actually a very interesting presentation. videos are available at http://www.usenix.org/events/usenix09/tech/ (I believe they are available to everyone, not just usenix members, please let me know if that is not the case)
there are a number of trends (not very surprising in retrospect)
if you have a false positive, the chances of anyone paying attention to further reports in that section of the code drop drasticly.
if you have a maintainer who looks at one report, the chances of them dealing with all of them in that area go up significantly
if a fix is produced as a result of a report, the chances of all the reports for a given area being looked at and fixed go up drasticly
if there is not an active maintainer of that section of code the chances of the reports being looked at go down drasticly.
a large percentage of real bugs and vunerabilities have had reports on that section of the code (note that this is _not_ the same thing as saying that a large percentage of reports have been found to cause real bugs and vunerabilities)
there is a significant push from kernel developers to avoid rushing to clean up the code to silence the warnings, there is a large enough correlation between these reports and more significant bugs that many of them want the entire section where reports are found to be examined, there is a significant chance that there is a more significant and subtle bug lurking in that area.