Someone else is developing their own app-specific rewrite tools. In this case app-specific refers to automating porting code from gtk2 to gtk3. The approach is similar in that patches are produced, but it doesn’t look like a patch aggregating tool is written yet. Instead of the elsa/mcpp magic sauce, clang is being used, so this is limited to C at the moment.
KDE folks are behind in automated code rewrites arms race, perhaps the trolls should try some pork to accelerate KDE3->4 transition
All kidding aside, it is awesome to see that less-manual-labour-through-compiler-assisted-refactoring approach is gaining mindshare.