[quotemsg=10701916,0,769386]I wonder if the motherboard having an onboard display port means Haswell IGPU will support WQHD.[/quotemsg]
Ivy's HD4000 already does. Actually, Ivy Bridge and Haswell support 4K resolution
http://www.anandtech.com/show/6270/ivy-bridge-gets-4k-display-support-in-october
The issue is, as noted in that article, with Ivy Bridge you need 2 Display Port outputs in order to drive a 4K monitor. Not many if any Ivy boards include 2 DP outputs. Haswell will support 4K over a single DP or HDMI cable, but I'm almost certain I have read HDMI will not support more than 30Hz refresh at 4K.
"with mediocre performance...maybe"
I have a Surface Pro that runs dual monitor with the Surface screen at 1920x1080 and extended to my Dell 2713 monitor @ 2560x1440. It performs just fine for any day to day stuff, (I watch HD NHL Gamecast streams on the monitor while surfing on the Surface screen) but no way I'd try anything gaming related.