December was marked with more expansions made in the problem sets available and by some behind the scenes work on the website.
Chapters 5 and 7 were each expanded to include problems for new sections written since the publication of the Preliminary Edition. The chi-square sections now have many excellent questions available, as does the section on inference for regression.
We also hope to release some new website tools in February. These resources should be useful to folks using OpenIntro: Statistics and other folks who would like some additional online resources but use other textbooks. While this work has been ongoing since early December, we will hold off until February to say much more — feel free to make guesses in the comments about what will be released!