With 5G starting to be more than just another G, I have heard of several technology visionaries say how it will change compute.  The idea being that if you can get these speeds in the datacenter, maybe the datacenter doesn't need to be in a cage anymore.  

While more high speed connectivity is exciting and who knows what fantastic gains we'll get from it, it's scary to think that now your "network" is spanning public networks even more than it already is.  Protecting at the network level absolutely will not work in these type of environments or even hybrids of these environments.  Each host will need to be able to protect itself and more importantly, the folks responsible need to be confident that each individual system is secured and constantly monitored to ensure that no exceptions take place.