Here's how I did that. First I created a ~/kde-stable.txt file with the following contents:
# bug #396359
... hundreds of packages omitted ...
~/arch-tools/batch-stabilize.py --arch x86 -i kde-stable.txt --repo ~/gentoo-x86/
You can do that too! Just clone my arch-tools repo, hosted by the Gentoo Overlays Team.
The tool creates a file batch-stabilize.log in the current directory (if it exists, new entries are appended to it), and the file contains all executed commands, their exit codes and output, so you can figure out what happened if something goes wrong.
It's also easy to create a list of packages in format accepted by batch-stabilize.py from the bug list. The bugzilla viewer is interactive, ncurses-based, and is simple to run:
~/arch-tools/bugzilla-viewer.py --arch x86 --repo ~/gentoo-x86/ --verbose
It's OK to omit --repo and --verbose parameters - it'll run faster and do less checks. You can also append --security parameter to only review security bugs.
I hope you like that, and enjoy either the tools, or they results - more up to date Gentoo!