Sorry if it's a really dumb/inappropriate question/request, or if the feature already exists somewhere I don't know of:
I see, for example, many (many!) changes in the upcoming release of tidyr. As someone who is planning a future course, or even as a user, I would like to be able to guesstimate when these changes will take place in an official CRAN release. The pivot_longer/pivot_wider thingy is a great example - probably should start incorporating this into course material, rather than gather/spread.
So if it's out there - where? If not - could be a good idea to add, somewhere, as in News.md, pkgdown or wherever. Thanks.
Usually there is no specific schedule for package releases and they are released when they are "done". This, of course, makes it a bit tricky to understand whether it's already a good idea to include new functionality into the course, but one rule of thumb might be to look into twitter/conference talks to see if major changes are to be expected.
To take your example of pivot_longer/wider - it's unlikely to change dramatically before release, so if your plan was to use it in the course, you can probably do that. It would require to use dev version of packages, but if you are using something like RStudio Cloud it shouldn't be too bad (I used it for the workshop with dev versions and it worked out quite nicely).
There are several steps that must be taken before a package is released, and we (the tidyverse team) don't control all of them. However, we do keep track of them and use a specific checklist in preparation for release (see current tidyr release issue below, for example)
We're starting to use milestones as well for some packages.
Unsurprisingly, you're not the first one to ask for a date on this. With packages that have a large number of dependencies, the first set of steps is not insignificant (see, for example, the description from the ggplot2 3.0.0 release post)
I've asked Hadley to jump in with a fuller answer to this, but those links can get you started.
For packages that have a longer release cycle (i.e. lots of reverse dependencies and we've had to make a backward incompatible change) we typically wait until between initial announcement and release; in the tidyr release issue you can see the next step is planned for Sept 9.
