Update: Here's HTC's official statement regarding the update, which elaborates on the changes in greater detail:

As part of our ongoing commitment to ensure customers are receiving software updates that improve their user experience, we are pleased to announce our next upgrade for the HTC One X will be released on August 10th.

The primary update will include an upgrade to Android version 4.0.4 (Ice Cream Sandwich), in addition to an improved Sense experience which will: enable the ability to map menu function to the 'recent app' key (improving visual presentation in non ICS apps like Facebook); improve tab management in the browser with a dedicated tab switching button and enhance camera capabilities such as white balance and continuous autofocus.