You should of course be able to share the iPhone 4G/5G connection via Ethernet to computers or other devices using an USB/lightning to Ethernet dongle attached to the iPhone.
I can only assume that Apple is currently working on this!
Personally I would like to connect the iPhone directly to my WiFi router without using a computer between the phone and the router. This would allow for a simple and quick backup solution when the regular internet connection is down.
I'm not sure I understand the comments made by Lawrence and 100clicks? Do you mean that you don't need this function? If so, thanks for your valuable input!
Personally I never understood why they make underwear in so many different colors? Just keep to black and white! Also, I seldom eat pineapple....