Gunnar Diepenbruck wondered several weeks ago whether or not an Apple LED Cinema Display could be connected in some fashion to the USB-C port of a 12-inch MacBook. I'd extend that question to ask about the Apple Thunderbolt Display as well. I waited to answer this to see whether a cable was forthcoming from Apple or third parties. None has yet appeared.
USB-C can carry DisplayPort data over the port, so this should be a possibility if the market were big enough to spur manufacturers. I have spotted one USB-C to Mini DisplayPort adapter for about $35, but it's being sold under several names, and is manufactured by a generic-labeling firm in China. I haven't yet tested it, and thus am not linking to it. The adapter is just for video, and thus no other USB devices (carrying power or data) can be connected to the MacBook if it's in use.
There are several DisplayPort (and HDMI) cables, but they all require a monitor to have an adapter plug. Apple's monitors have either a hard-wired Mini DisplayPort or Thunderbolt cable (which uses the same form factor as Mini DisplayPort) with a jack on the end.
One potential solution is to get a Mini DisplayPort adapter. Monoprice makes a female-to-female Mini DisplayPort coupler to chain cables, but it consistently receives negative reviews as it apparently only works with the 1.0 standard, rather than the widely supported newer 1.2 standard that's required for newer monitors.
What might be a solution is an ungodly combination of:
- StarTech's female Mini DisplayPort to male DisplayPort adapter ($4.50)
- A female-to-female DisplayPort coupler ($13.50)
- A DisplayPort-to-HDMI cable (as little as $6)
- Apple's $79 USB-C Digital AV Multiport Adapter, which has an HDMI port on it in addition to pass-through USB-C power and USB Type A 3.1 for data
The display cable would plug into the StarTech adapter; the coupler would change the gender, allowing the male-to-male DisplayPort-to-HDMI cable to work; and the HDMI male end would be plugged into Apple's adapter.
I don't have an Apple display to test this on, and goodness knows if it'll pass everything through without distortion. But conceivably, the DisplayPort data from the Apple monitor would simply be sent across multiple cables without conversion.
The female-to-female coupler and DisplayPort-to-HDMI adapter could be replaced with Cable Matters' female DisplayPort to male HDMI adapter ($14), but that may introduce signal conversion and make the likelihood of success lower.
Of course, with Thunderbolt 3 on the way, which will work over USB-C, a future MacBook could work with a USB-C to Thunderbolt 2 adapter--or Apple could update its monitor to have different methods of connecting.