In short: If you don't update your BIOS of X79-UD3/UD5/Assassin 2 to F7 or later, you will have the risk of burning the mainboard when you OC. Three solutions for the end-users:

• Recall all motherboards with earlier BIOS revisions, and suggest users to update them to F7 or later by themselves if they notice that message.
• If you happened to experience the same symptom after updating to F7, then they provide life-time warranty for similar faults in the future.
• If you still have concerns regarding this matter, you can refund your board with Gigabyte at any time.

Currently, the newspost is only available in Chineese, but I assume similar options will be available to other regions.

F7 BIOSes can be found here: http://hwbot.org/forum/showthread.php?t=33752

(Translated with help of Google Translate)

GIGABYTE X79 series motherboards provide some professional players firmware (BIOS) version, such as overpressure by overclocking, the fear caused by abnormal or over-temperature burning conditions, to ensure the best usage, please access the user immediately update Gigabyte X79 BIOS or call toll-free technology, we will appoint someone to serve you.

Statement as detailed below:

• GIGABYTE full recall on all sales channels for a particular version of the X79 motherboard firmware (BIOS) update, or by consumers to conduct its own firmware update, to ensure the best interests of consumers.
• GIGABYTE X79 for the protection of consumers to use extreme overclocking performance, where the updated version of the BIOS F7 (including the later version), still caused by overclocking the phenomenon of burning models are given a lifetime warranty (GA-X79-UD3, GA-X79 -UD5, G1.Assassin 2.
• Products of the company's X79 still worries consumers may be unconditional return policy (please contact the Customer Service Center Gigabyte).

GIGABYTE X79 motherboard for the (professional player firmware version) by the user overclocking overpressure, the fear of failure may be caused, Gigabyte Technology professional players and consumers have caused unnecessary distress apologize. The Company will expedite the processing of the above statement and continued to approach the concept of the highest quality, has introduced the industry-leading Ultra Durable motherboards.