In my 5G: A 2020 vision presentation, I argued that some of the technologies that will be necessary for 5G is in fact independent of 5G. One such technology is NFV. Having said that, I also argue that the minimum prototype for 5G would require an NFV based implementation.
Tieto gave an interesting presentation in our last Small Cell SIG event explaining how the network will be implemented based on NFV. The presentation is embedded below:
There is also an interesting paper that expands on this further, available from Slideshare here.