AnandTech got to hear at Intel's IDF 2012 in San Francisco that the chip giant is working on a new driver update for Ivy Bridge's integrated graphics. Said to be available in October, the update will add support for displays with a 4K x 2K resolution as well as hardware-accelerated 4K video decode.
The only problem however is that you'll need two DisplayPort outputs to drive a 4K screen from an Ivy Bridge system. This restriction will fall away on the Haswell platform.
You'll need to use two DP outputs to drive a 4K panel from an Ivy Bridge system, which unfortunately makes it so most existing Ivy Bridge systems won't be able to drive the higher resolution panels. Haswell will support driving a 4K display off of a single DP output or HDMI.