Hey there, kiddies, Uncle Billy really hopes you're not still using Windows 98 because starting today his mom and pop operation is no longer offering technical support for it. Internet Explorer on the fritz? Task bar disappeared? BSODs getting you down? Well, it's no longer his problem, so tough cookies.
In addition to ending [paid, over the phone] technical support, Microsoft is no longer offering security updates for its old OS. There's an estimated 70 million users out there who are still using the affected software, Windows 98, Windows 98 SE and Windows Me. How this might affect the propagation of worms and viruses can only be speculated, but considering most remaining installations of Windows 98 are home users, it's safe to say that the magic 8 ball reads, "outlook not so good."
Microsoft originally wanted to end all support for its legacy OS by the end of 2003, but following customer complaints decided to extend paid support for a little while longer. That time has now ended. Let the fun begin!
Microsoft shuts down Windows 98 [BBC News]