FYI, the Thunderbird email client was also updated to 1.5.0.8. http://www.mozilla.com/en-US/thunderbird/
Yep, got that notice and took care of it. Looking more closely at the info with the security notice, it said that the vulnerabilities in Firefox 1.5 don't exist in Firefox 2.0, so no need to update. As long as 1.5 remains supported, I'm probably wait for a while yet to go to 2.0.