The end of IPv4 is near, but that doesn't mean the end of the Internet is here. The next chapter gets a new page turned. Maybe we will determine that IPv6 needs to go the way of IPX/Decnet/AppleTalk and some new system (non-IP even) will take over the world.
IMHO, there is no such thing like "the end of IPv4 is near", what is near is the exhaustion of the IPv4 address space for new allocations. Unfortunately, as Bill mentioned, IPv6 does not offer much more than an expanded address space, quite a different situation with the proprietary protocols you mentioned, then there is no much benefit/motivation for many to switch in a hurry. No doubt that we need to move forward and keep pushing to get IPv6 deployed, but it will coexist for many many years with IPv4 which will probably never go 100% away. My .02 Jorge