WPA update for WinXP available--what does it do?

[UNCjigga]

Saw this on Windows Update today:

Update for Microsoft Windows XP (KB826942)
Download size: 275 KB, < 1 minute
Wi-Fi Protected Access (WPA) support is now available for Microsoft Windows XP. This update provides additional wireless security capabilities for the latest generation of wireless networking equipment supporting WPA. After you install this item, you may need to restart your computer.

So what does this do for those of us with WPA networking cards/routers/access points? I thought drivers took care of this stuff already