[perlgeek]

As always in open source projects, there's the risk that a major contributor might drop out.

Barring that, there are three major technical things we want to tackle before the release: native, shaped arrays (compact storage of arrays/matrices of machine-sized types), the Great List Refactoring (GLR; mostly about speeding up list iteration and making things more consistent), and some Unicode-related tasks.

Any of those might prove more difficult than expected. I personally see the biggest risk in the list refactoring, because lists are rather central to the language as a whole.