We now have the ability to have (sane and meaningful) preprocess (and process) functions for all theme hooks:. I don't think there are many, but there are some theme functions that combine way too much data and logic along with presentation decisions. This makes it unnecessarily difficult for modules to adjust the data and logic decisions. Patch coming in a follow-up comment.
Passed: 13484 passes, 0 fails, 0 exceptions View
Passed: 13481 passes, 0 fails, 0 exceptions View
Failed: 13639 passes, 0 fails, 4 exceptions View