On April 10th, CodeIgniter 2's EOL date was set for October 31st, 2015.
I was expecting the EOL date to be a little further out, but I think it's a workable timeframe for Bonfire. Given this, and having released Bonfire 0.7.2 (also on April 10th), I am expecting to spend the time until then working on issues with CI 3 support. Pull requests and issue reports will still be welcome for all areas of Bonfire, but I only expect to have one more release of Bonfire (0.7.3) with CI 2 support. After the EOL date (October 31st, 2015), CI 2 support in Bonfire is expected to be deprecated.
After the 0.7.3 release, I will bump the version to 0.8.0 (or should it be 1.0.0? I think that version number has some implications beyond what I wish to imply, but 0.7 to 0.8 doesn't seem like enough). At that time, I will start removing those CI2 compatibility measures which have the largest impact on performance (the most obvious of which would be to enforce the CI3 filename standards). I will also switch the default $system_path to load CI3, include CI3 in the download, and remove all CI2 files except those which have been modified for use in Bonfire. So, in the next version after 0.7.3, the process for using CI2 will be similar to the current process for using CI3: filenames will have to be fixed for CI3 compatibility, CI2 will have to be downloaded separately, and the $system_path will have to be changed to point to CI2.
As Sprint and Bonfire-Next mature, the direction of Bonfire will likely move towards creating an migration path to those platforms. For now, though, my priority is to ensure that Bonfire is still available on a stable, supported base for both existing sites (including my own) and new development.
-- Mat Whitney