Just got word from Mark Fox @ MaxReboot that Jetway have released a new ATI driver for Win98/ME version 4.13.9021! Here's what he's saying:

It's dated 02/28/2002 and it contains updated OpenGL ICD among other files thus expect a few bug fixes over the last set and perhaps performance increases :)

The following cards are listed as being supported:

Radeon 7200 / Radeon

Radeon 7000 / Radeon VE

Radeon 7500

Radeon 8500

Download ATI Radeon driver for Windows 98/ME 4.13.9021