Everything dies.
> Ask Kenneth Reitz for example. He says he will use Python 2 forever.
So, assuming this currently-stated intent never changes and Reitz is immortal, Python 2 will always be in use.
The first of those premises is somewhat suspect, the second even moreso.
> There are a lot of companies with huge codebases who never will port to Python 3.
That's probably true. Its less likely true that those companies will never port off Python 2.
Python itself might die when Python 2 dies, and arguably, Python 3 makes that more likely.
Everything dies.
> Ask Kenneth Reitz for example. He says he will use Python 2 forever.
So, assuming this currently-stated intent never changes and Reitz is immortal, Python 2 will always be in use.
The first of those premises is somewhat suspect, the second even moreso.
> There are a lot of companies with huge codebases who never will port to Python 3.
That's probably true. Its less likely true that those companies will never port off Python 2.