One of the comments that I hear a lot (and I am sure to receive on this site) is "But I don't need IPv6 for that! I can do that in IPv4!"
It is true that a lot of what we can do in v6 we can do in v4 as well. That's because v6 is based on v4 and needs to accomplish all the same tasks; they are both just Layer 3 routed protocols at their heart. In terms of basic functionality, there isn't a lot that IPv6 can change/introduce that wouldn't break existing networks.
Instead, what v6 offers is the ability to simplify and standardize a lot of the things that were difficult in v4. It makes hosts easier to configure (but v4 can do that!), it makes security easier to setup (but v4 has security!), it makes end-to-end connectivity easier to establish (but v4 can kind of do end to end if the specific application is designed to work around NAT!)
For example, using IPv4, write an application that allows my machine to connect to your machine through a NAT on each end so that we can play head to head games. Um, well, that's......hard. In v6, it's easy. It just works.
How about this: using v4, write an application that allows my Windows machine to setup a session to your Linux machine so that we can perform host authentication and encrypt data. Oh, and no, I don't have SSH on my box. Umm...well, you could...yeah. With v6, it just works.
Anytime an enterprise can simplify operations, anytime device setup can be simplifed, anytime we can remove complexity from the most number of users, IT finds benefit from that. That is what IPv6 is all about.
So, can you do that with IPv4? Quite possibly. But with IPv6 I can do it for less money, in less time, while using standardized, proven security.