
I use a cron job to download the errata web pages from http://www.openbsd.org/errata.html (and, errata38.html, etc) once every three hours. I have a screen scraping script I modified to create an RSS feed for the OpenBSD Errata.
Finally, I use the GetRSS plugin to display the feed on my Wordpress pages.
I've made the RSS feeds for 3.9 and 3.8 available as well (note the RSS links to the right).