Yes, all of the attention is on Drupal 8. D8, will be amazing! It totally makes sense that when folks talk about Core development that they think about the latest version. Sometimes though it seems that we forget that there are two stable releases with hundreds of thousands of sites using them for every development version of Core.  If this proposal gets accepted, which I think it will, there will 3 supported releases of Core for a few months when the Drupal 9 branch is started.

So we know when Drupal 8 is released that there will still be 3-4 years where we are going to be working with Drupal 7 sites. 

The whole development process of Core demands that for a bug to be fixed in a stable version of Core, it has to be first fixed in the development version, as per the Backport Policy. This ensures that the bugs identified in a current stable release are fixed in the development version and then brought back to the stable releases.

Unfortunately, it seems that the community has forgotten to check back and ensure those bugs are fixed in the stable releases. In a check I did earlier today it showed that there were nearly 250 open issues which are fixed in Drupal 8 and ready to be backported to Drupal 7. There are D7 Core issues that have been waiting for review for over 2 years! There are a lot more that haven't been fixed yet in D8 but will be added here when they are. Of those, the vast majority are bugs. Looking at the Priority Levels there are 8 bugs listed as critical and 25 bugs listed as major, but when there are more than 800k sites using it, that's very signifiant.

This really should be seen as good news though. This is a great way to get people involved in Core development who haven't been before. There's a way faster return on all of these bugs, than any of them in Drupal 8, because you will be able to use the fixes now with live sites. Plus, we've already got a model to emulate that we know works. Also, this is a great opportunity to get to know better a tool that you use every day.

So if you aren't already a Core contributor, here's a great time to start. Patches need to be reviewed, improved, and ported. When they are properly reviewed, they will be marked Reviewed and tested by the community (RTBC) and hopefully brought into an upcoming maintenance or security release.