Comment 19 for bug 1458327

This bug is not limited to the dell hardware but also affects the MacbookAir6,2 model. Some more potentially relevant info:

05:00.0 PCI bridge: Intel Corporation DSL3510 Thunderbolt Port [Cactus Ridge] (rev 03)
00:02.0 VGA compatible controller: Intel Corporation Haswell-ULT Integrated Graphics Controller (rev 09)

Some more information playing around with it:

Plugging in the monitor makes everything black but the cursor shows, as described. Unplugging the monitor doesn't fix it. ctrl+alt+backspace shows the desktop briefly before X crashes.

Setting up the monitor in Marco and then switching to Compiz will work, but unplugging it will leave the laptop monitor unusable, and plugging it back in also has pretty mixed results. However, after the monitor has been set up (in Marco), you can restart X and log in and use Compiz and it will initialize properly.