This has been in the cards for so long and there has been so much (often uninformed) discussion I’m actually surprised the FAQ has an entry titled “I didn’t hear anything about this till just now.”
I switched all my projects to Python 3 gradually (targeting 3.5, a little over a year ago), and it’s been truly painless. Having used it since 1.2, I can appreciate how far it’s come and how things have changed since (literally) the turn of the century.
It’s still my go-to programming language, and I’m looking forward to PyPy and Cython improvements in ARM - it will never be the fastest language on the planet (I look to plain C, Go and Java for that), but its ecosystem still gives me the most bang for the buck with the least hassle, and that, I think, is the real reason why it’s been so successful over the years.