Via Philip Wadler:
[...] Guido van Rossum and others have started serious design work on Python 3000, a next-generation successor to Python:
As a Python user, this interests me and concerns me in equal measures. It could easily fall into the same trap as Perl 6. People considering a language transition will also consider "competitor" languages, not just the designated successor. In fact, the announcement of a successor language may serve to validate those competitor languages.
It's also interesting to consider other language transitions (such as C to C++, or Java to Java 1.5), and the ways in which they succeeded or failed. Designing any language is hard; designing a successor language seems even harder.