I just wrote this on the CodeIgniter forums.

There’s been some notable work dropped into CodeIgniter recently. We’re working on finishing up a few things for a 1.6.2 release. A few noteworthy items include enhancements to Active Record, a new compatibility helper to allow the use of several common PHP5 only functions in PHP4 and come enhancements/behavioural changes in unit testing, form, url, directory and download helpers.

There have been several speed and security enhancements as well, in both CI “proper” (and various libraries and helpers), and of course, the usual round of bug fixes and doc changes. In fact the documentation has grown by 2 pages (Reserved names and Common functions).

If you want to leave a note, by all means feel free. I'm closing comments on this post to keep everything in one place (in this case, the CI forums).