Creative Labs sends along a statement refuting claims by Asus that their latest audio cards offer EAX 5 support:

With respect for you and your readers, we wish to share this important information. With its recent driver updates, Asus is misleading its customers by suggesting that its sound cards now support EAX 5. Asus sound cards do not support EAX 5, nor do they support EAX 3 or EAX 4. There are a small number of PC game titles that specifically query the audio device on the system to see if EAX 5 is available before they will attempt to render more than 64 3D simultaneous audio voices. The new Asus drivers are falsely reporting EAX 5 capabilities in order to get these games to ouptut 3D audio on Asus sound cards. Asus customers are not getting a genuine EAX Advanced HD experience with this driver update. Furthermore, the several hundred games that support EAX 3 or EAX 4 for delivering in-game effects will not provide those effects from Asus sound cards.