In the examples talked about, the spray-on antenna was used to turn a tree into an antenna that could transmit VHF to an airplane 14 miles in the air, improve the stock antenna of an iPhone, and even transmit signals over a mile when underwater. The spray-on antenna is also said to consume less energy than traditional antennas. Also, since it is spray-on, you can pretty much coat anything with it, eliminating the need for cell towers (i.e. spray it onto trees, buildings, signboards etc).
No mention of when we can expect it to be used, but any technology that promotes power saving, and reduces the amount of unsightly towers we have in the world is good in my book. Check out the Solve for X video below: