Now I have to either take everything back to 2.7 or keep believing that I will finally manage to work it out with 3.
How is that going to kill the "momentum" I received and change my feelings about Python? It's not going to change them. I enjoyed every single moment of coding so far, even those very first ones where I kept inserting curly brackets everywhere. So, if it fits my needs, I am going to use it in future projects as well.
How is that going to change the industry's feelings about Python? Who knows? But I doubt the industry worries about "momentum". If you are using 2.7, keep using it until Python 3 is usable for your. If you are not using Python yet but you want to, do your research beforehand (something I falsely didn't do) and decide what's best.
Now, how long is it going to take for the major libraries/frameworks to be Python 3 compatible, nobody can tell. And it's funny as we are approaching the "3.2" version already.
But, honestly, who cares? Is a number more important than the language itself?
It is not the job of application developers to keep up a languages "momentum", its the language creator's job. If he underestimated the momentum of the current version and didnt bother to inter-coordinate incompatible language upgrades with his users and introduced a new trademark-diluting version anyway, you cant simply blame the users for not investing time and money in order to "protect the language". They are not obliged to follow whereever he leads, and if he wants to lead without caring about his followers, they might just decide not to follow any more. Who guarantees that he's not going to pull a Python3 again 5 years down the road and then sing the same "not updating is momentum killing" song again?
It sucks, yes, but it'll move Python 3 forward...
Nah, people are just progressing. Over time, certain deficiencies are recognized in programming languages, and they get repaired. In the case of Java, generics were sorely missed, so they got added. In the case of Python 3, unicode support will be much better streamlined, and standard libraries get a bit restructured; some names are cleaned up. It's not like half the language changes. Not even 2%, is my guess.