I don't have hardware, but Narrator works in emulator. Link to manual still is not available, so I don't know full list of features. There are 2 modes of operation, in one of them it activates controls in same places where you touch them, in other it represents content of the screen as a tree for navigation: moving finger left/right activates previous/next control, moving up/down changes level of tree. The problem is that I don't understand what thing triggers switching of modes, I did it in the emulator unintentionally. In any mode it reads content of activated control; double tap in any place of screen allows to use active control, some controls have additional action for triple tap. It's possible to use 2-finger gestures to scroll vertically and horizontally, it announces percentage after performing gesture. Scrolling works on specific level of navigation tree, sometimes it can be confusing.
Common controls are all accessible.
On-screen keyboard is shitty: every key must be activated before use. So typing is probably very slow.
In system tray area it could read every icon (level of network signal, battery, clocks...), but I could not find a way to open Action Centre.
Application switcher is bad, I could not find a way to use it properly. Button for closing apps works, but it's announced as generic button without text.
Accessible standard apps: Alarms, Data Sense, Internet explorer, Maps, Messaging, People hub, Phone dialer, Photo hub, Store.
Inaccessible standard apps: Battery Saver, Calculator, Calendar, Office, OneNote, SkyDrive, Skype, Storage Sense.
Standard apps where many buttons are unnamed, but blind usage is probably possible: Camera, FM Radio, Games hub, Xbox Music.
Emulator contains old versions of everything, so real phone could be different.
You don't need to implement full USB for USB power delivery. USB's data transmission is not used in it at all.
Detection of power delivery plugs is mechanical for standard A connectors (their male standard-A connectors are 1.3 mm longer so they could be inserted deeper in female power delivery connectors than conventional connectors so metallic shield connects detection pins) and based on detecting resistors and capacitors between ID pin and ground and power pins for other connectors.
For voltage negotiation new simplified bus and protocol was invented; it uses high frequency transmission on the same pin as power.
IIRC USB Power Delivery requires to provide 5V and 12V if you want to provide 20V. According to their FAQ question about compatibility with Microsoft Surface and Chromebook Pixel (https://www.kickstarter.com/projects/215201435/dart-the-worl... ) they don't have 12V support. Probably they are not ready for USB 3.1.
I'd guess 12V is for lower-power devices, where (slightly) cheaper 16V-rated (the next step below 25V) capacitors can be used. The other parts (switcher ICs and MOSFETs) are usually rated for much higher, and the system would be fine with a 20V input if it weren't for the 16V caps.
E.g. the EEE 1000HE uses a 12V adapter, and it has 16V caps in its power circuit. Probably the same for the Surface/Pixel.
I think you're overemphasising Unidan's comments. Unidan is talking about plantations of trees, not crops (edit: trees have a much greater reach and ability to pull nutrients from the ground). Yes, if you clear a forest for the crops the first time you get a net release, but after that, you're basically recycling carbon. True, you might get a small amount of carbon drawn from the soil, but the vast bulk of a plant's mass comes from carbon in the air.
In any case, it's still far, far better than having the entirety of the carbon in the fuel pulled fresh from long-term stores - the maligned 'green argument' above.
(edit: I am also a biologist by training, though not an ecologist as Unidan claims)
Asymmetry. It's not an accident that movement is on the left and aiming is on the right, both on controllers and PC. On PC, though, you can move the mouse to the left side of the keyboard and rebind your movement keys if you want to.