GIMP 2.8 doesn't allow to save usual image file formats (jpg, png) via Save dialog

I remember reading on heise (german) that someone wrote a plugin to revert back to the old functionality.

Runnning the following commands in a terminal will download the latest version of the plugin to Gimp 2.8's config directory and make it executable:

gimp_dir=".gimp-2.8"
wget https://github.com/akkana/gimp-plugins/raw/master/save-export-clean.py -O ~/${gimp_dir}/plug-ins/save-export-clean.py
chmod a+x ~/${gimp_dir}/plug-ins/save-export-clean.py

But I have to say that it's not a big deal learning the new shortcut Ctrl+E. Also having a clean distinction between destructive export and save is actually a good thing.

Starting from GIMP 2.8 we need to use the "File → Export" or "File → Export to..." menu entries, or alternatively the Ctrl+E or Ctrl+Shift+E keyboard shortcuts respectively, which will result in the Export dialog to allow you to save the work in your favorite image format.

The former Ctrl+S and Ctrl+Shift+S is now used to work with the project only. To save the project or "Save as" the project.

Good luck!

For the comment of @Eric Leschinski I am dropping this edit:

That's about how you use your software. Many people uses mouse and it's ok if they love to do so. Personally I made my process as OpenFile/Tweak/Export/CloseFile[CloseGIMP] in a faster way by doing the CtrlO/Tweak/CtrlE/CtrlW[CtrlQ] and it takes 3~5 seconds (depending on your machine's speed. For the "Save as" Process it takes just one more step but it did the same before. So I suggest you to start by tweaking your key binding in order to make it faster. Good luck!