Path is the same as before. It is the hierarchical tree of employees (or whatever you're displaying) separated by dashes. So an employee named Bill Williams whose bosses are Jim Smith and Fred Clark would be "Fred Clark-Jim Smith-Bill Williams." It's a setting you can choose in QlikView to display as a tree.
Name is the name of the empoyee (or whatever you're displaying). This is needed to properly map and reconcile the boxes with the hierarchy.
The pop up content is where you set what you want to show up in the pop up. This is the main improvement. Before what was shown here was specific, but now you can set it to anything. In order to mimic the pop-up from the extensions example demo (http://us.demo.qlikview.com/detail.aspx?appName=Extension%20Examples.qvw) you would set this to be: =[Employee Desc1] & '<br>' & [Employee Desc2]
The new extension will not overwrite the old one and will be shown in the Extensions list as Org Chart v2