Here's an interesting web site I found today.  It describes how Microsoft supports its products over time.

Microsoft Support Lifecycle

At the bottom there are links to various listings for each and every product, showing their current status.

For example, here's is the complete product list:

http://support.microsoft.com/gp/lifeselectindex

So, you can see things like the retirement of Windows 98.

Since just about everyone owns a Microsoft product, it is good to know that there is a place to find the up-to-date info on product retirement.