I ordered my Y580 on 6/19 and finally received it on 7/13 - ridiculous that it took that long!
The laptop was great on days 1 & 2 but on 7/15, when I turn the laptop on, the screen is completely screwed! There are lines flickering all over the place to the point you can barely see the windows logo. I connect it to an external display and there are no problems. I restarted the laptop several times and switched the graphics global settings to always use the onboard graphics and the 660M but that didn't work. It's clear that this thing is a lemon and will be calling on Monday to get a replacement. Another month of waiting...sigh. Lenovo needs to get some tips from Dell on quick distribution.