The big problem with supporting graphical UI is when you need to ask somebody to follow your instructions over the phone. Quite frankly, it's a nightmare. The less the person on the other end of the line knows about operating a computer, the worse this nightmare tends to get.
Here's a few commands you can get the person you're trying to help on the other end of the line to run to help you bypass a lot of the troublesome back and forth conversations, and head straight to what you need them to do to troubleshoot their problems.
ncpa.cpl - Opens up network connections window. This comes in real handy when you need to get somebody to open up the network connections over the phone. Navigating through the Network and Sharing Center over the phone is just insane.
services.msc - Launches the system services management console. Start, stop or just check the status of all system services from one place.
cmd - The most useful tool of all. If you know a lot of command line commands then the command prompt is a treasure trove of tools available for troubleshooting various problems. I'm no Guru here. I just know a small fraction of the things that could be done. But that's plenty in some cases.
appwiz.cpl - Brings you straight to Add/Remove Programs. Windows XP's control panel was still pretty simple, but Windows Vista/7 made things really clumsy, if you asked me. With appwiz.cpl you won't have to hunt through control panel. Alternatively, you could also do a search for 'Uninstall Programs' from the Start button search box.
This is obviously a incomplete list of Windows commands available. There's simply too many to list in a single post. These are simply some commands I've come across that I've found to be useful in some way.
I suspect Metro UI will only make life unnecessarily more challenging for tech support. Know any more commands for bypassing the oft confusing Windows UI? Share them in the comments. I'd love to learn more.