Looking at the current way drizzle support is being implemented, it seems like it's going to be made with a PMA_DRIZZLE constant and a lot of if()'s all over pmas codebase. That sounds somehow messy to me. Isn't there a way with some git branching magic + regularly merging back or "preprocessor" (the conversion scripts before releasing pma, like its done with pootle) directives to keep those things seperate?
Looking at the significant differences between MySQL and Drizzles this seems like a non-trivial change on pmas codebase. I don't know how the typical use cases are but I don't think a typical user will require phpmyadmin to be able to switch between MySQL and Drizzle. So what about releasing a drizzle supporting version of pma seperate from the mysql supporting version?
If another noticeable MySQL fork comes out that pma wants to support, things would only get messier in the codebase. Or if it turns out that the Drizzle Database isn't such a good thing and the project dies it would be easier to remove it from pma when the code is being kept seperate.