When I fly, I love the onboard WIFI you can be productive and not face endless emails when you have to land.  I figured out that you can also Skype message and text message but you can’t do video calls ...  I'm sure that will change soon.  

My question is this; why do I get charged $39.95 on a transcontinental flight (5-6 hours) and yet I read United are planning to charge $17 for the entire Los Angeles to Sydney flight (14 hours).

That is a massive price difference and good on United for taking an aggressive approach to building customer loyalty by getting the price right.  The domestic providers ought to sit up and take notice.