This page contains quick drafts of various "ideas" for Wikimedia projects.
{{#media}} for wrapping media fragments in a skin-independent way: T318433#10397735.asMarkedWikitext(), .asHtmlString(), .asDom() etc to coerce to different forms. If the argument is an HTML tree but the fragment handler expects a wikitext argument, the argument is provided as a strip marker ("marked" wikitext); similarly if the fragment handler returns an HTML PFragment but is passed into a context expecting wikitext, the HTML gets stuffed into strip state. More thoughts here.{{foo|bar=<nowiki>bat</nowiki>}} is another pattern commonly used; further discussion here and {{#kv}} is discussed in the dozen visions for wikitext.typeof="mw:Raw" and typeof="mw:DOM" on subtreesembedsHTMLInAttributes/embedsDomInAttributes properties in Module_Configuration_Schema#tags

Annotation Service -> Content Translation paragraph relations -> Better UI for finer grained relations -> Maintaining translated content
Annotation Service -> Comments in VE
Annotation Service -> Precise citations
Merge tools -> Resolve edit conflicts w/ save
Merge tools -> Offline editing
Merge tools -> Maintaining translated content (ultimately replacing language converter)
Merge tools -> multiway merge (both english & german -> czech)
The following proposals were recommended as well-written templates:
Other folks have fascinating "ideas" pages as well: