UPDATE: I have done more research and found that the Thunderbolt new protocol via a Thunderbolt port on a motherboard, will convey data, or video and does so at 10 gbps. It does function as a video port in the same way as DVI(digital) or VGA(analog), and can convey data same as you would use a firewire or USB or USB3 to an external HDD, etc. . It is a digital port and is the same thing known as "mini display" port.
I ordered an adaptor for HDMI to Thunderbolt(mini display port), roughly 15 dollars US, and I do plan to run my second monitor from its DVI port via a DVI-HDMI cable, and thence from the HDMI end into this new adaptor and into the Thunderbolt port on the back of my DZ77RE-75K motherboard. My main monitor will be run as it is now, into the HDMI port.
I was not previously aware of the Thunderbolt capacity, speed, or video-transmission ability.
I purchased a HDMI to Thunderbolt adaptor from ebay, and it does work correctly to connect a HDMI monitor(with no Thunderbolt connection on the monitor) to the Thunderbolt port on the back of the DZ77RE-75K board. I have two monitors connected and working in the extended display mode; one HDMI monitor is direct to the HDMI port on the board's back, and the second is via the HDMI to Thunderbolt adaptor to the Thunderbolt port on the board, as stated above. I am happy with my two monitors functioning as before my upgrade to the Intel board, when I used an older 256 mb AMD discreet graphics card to power two monitors. I am still using the onboard Intel HD 4000 graphics and using the Intel i7 3770 CPU processor with the Z77 chipset of the board and 8 gb ram. I use Photoshop CS5 to edit large 20 mb photos and my system is working as well as with the aforementioned 256 mb discrete graphics.
Just wanted to let others know that this is an inexpensive way to power two monitors without buying a graphics card, if your needs are similar to mine(I do not use my system for gaming, have no time for it).