I'm now trying to find some list of supported web application for web gateway(like TrustedSource ref. guide), but only what I found was - Popular Applications - McAfee Labs Threat Center - there you can only search for application, but for customer I'd need list of the recognized web applications that McAfee WG supports and possibly also what it can control for that application(like download, upload, post, etc.)
AFAIK, I don't think there's an online list for the application control feature. The only lists I know of are the lists under Lists->System Lists->Application Name. It doesn't exactly make it easy to do a mapping between application category and sites that fall into the various application categories. And, I have no idea how often these lists are updated.