Now this is problematic, because I have never seen any LGA1155 motherboard with more than one DisplayPorts.
This probably means that the waste majority of existing LGA1155 motherboards (including the high-end ones) don't support 3-display setups, even thought some have as much as 4 monitor ports. (DisplayPort, HDMI, DVI, D-sub.) See here: http://forum.giga-byte.co.uk/index.php?topic=9195.0
However, the situation might get better with the introduction of motherboards with Thunderbolt ports.
As Gigabyte has demonstrated, connecting DisplayPort splitters to Thunderbolt ports, one can drive 4 1920x1200 monitors from 2 Thunderbolt ports. (See here: http://www.gigabyte.com/MicroSite/323/4k.html )
Now this brings various interesting questions.
1. The splitter they are using is a standard DisplayPort splitter, it has nothing to to with Thunderbolt. They even explain the DisplayPort 1.1 is required for this. Does this mean that I could split the DisplayPort output of any Z77 motherboard, add a third monitor on a non-DP port, and start happily using 3 monitors? Or is this something that needs to be specifically supported by the motherboard BIOS? Are vendors adding this feature?
2. All the specs said that Intel graphics support 3 monitors. What I see is 4 monitors. How is that possible? Does the GPU see less monitors than for? Is the splitter talking to the GPU as one monitor, splitting the image into two, hiding the two monitors from the GPU? Or is it some BIOS trickery?