With the LTE version of the new Nexus 7 2013, tethering or Internet sharing is finally possible. Even on the 3G model, the Nexus 7 could not be used as hotspot, but this functionality is enabled in the Nexus 2013 LTE model.
If you want to use it as Wi-Fi hotspot, go into the settings and under "Wireless & networks" and tap on "More" button. There you can select "Tethering & portable hotspot" option. In the next menu, you can choose whether you want to start the hotspot via WiFi, Bluetooth or USB connection.
Like its predecessor, I would prefer to use it as my Smartphone but unfortunately, call functionality is not present. This is something that is only present in Lenovo and Galaxy Tab tablets (galaxy tab 3 and tab 2 offer it).