The gist of which is, go download the latest version for a security fix.
Also, if you're like me and are curious about usage stats, the article also says:
Microsoft's browser now has a 88.9% share, while Firefox's share has risen just over a point to 6.8%. Previously, IE dominated more than 95% of the browser market.
So Firefox is making in roads...but is actually less common than I'd think by talking to my flist ;^)