Here's a list of things that need to be done before the dialogs API can be considered complete:

• Review which convenience constructors should be included
• Decide on inclusion of Action API
• Decide on inclusion of ButtonBar API (for OS-specific button placement)
• Discuss desire to include support for non-modal dialogs, and how far to take it
  
• Test dialogs work well in FXML / Scene Builder
• Decide on which additional high-level dialogs should be supported (e.g. font chooser, progress, command link, login, etc)
• Decide on whether to include a wizard API
• Decide whether to include 'lightweight' dialogs (e.g. lightbox dialogs). Need a glasspane API (public or internal) for this to happen.