This is a brainstorm page, raw and ready.

Graphics capabilities

• cairoification
• SVG 1.1 complete and performant
  • solid testing of opera-interop
• Canvas improvements
  • OpenGL ES context?
  •  %age width/height
  • finish Safari compatibility
• 3D markup for retained-mode and model manipulation?
• transforms/filters for images and canvas
• XUL2D
  • affine transformations
  • non-affine transformations (selected only?)
  • transforms expressed in CSS
  • declarative animation
  • pan, zoom, scale
  • translucent and non-rectangular windows
  • text and others on paths
  • flow and flex around complex shapes
• 3D work
  • X3D?
• Level of detail
  • Thumbnailing
  • fast-but-general for animations
  • content model LOD?
• downloadable fonts
• vertical text
• printing improvements

JS2

• packages
• namespaces
• classes/MOP
• type annotations
• operators
• E4X rationalization (E5X)
• debugging infrastructure
  • mixed-lang (python, C++, etc.)
• GC improvements
• security model revamp
• E4X<->DOM glue

Python for XUL

• XBL language neutrality
• performance?

XUL' and XBL2

XUL'

• improved template builder
  • data providers for sqlite, RDF, filesystem, computed-by-JS
  • produce arbitrary content
  • unprivileged use
• XUL box model
  • hyatt's spec and CSS properties
• user-implemented layout managers (a la grid, stack, deck)
• improved widgets
  • tree (esp "view" API), sort for unprivileged content
  • grid
  • stack and event handling
  • support for large-scale data containers (not just in tree)
• overlays
  • synthesized onload (at the least: declarative event handler merging)
  • xpath insertion-point selection
  • fallback locations
• editing improvements
  • NVU changes landed
  • richer editor interface
• whitespace preservation in XUL, for editor roundtripping
• error reporting
  • debugging/tracing
• Cocoa widgets
• remote XUL
  • sync/async for DTD loading, etc.
  • security issues
• single-file apps (script, XUL, XBL, DTD, CSS)

XBL2

• XBL attachment model
• XBL capability/security model
• language agnosticism
• custom rendering of widgets (merge in XTF)
• inherits= for CSS
• sXBL specification

Web app improvements

• security UI consolidation
• offline detection/pinning/behaviour (a la Alchemy)
• client-local storage a la Hixie

Embedding

• Unification of "embedding" APIs (nsIWebBrowser) with XUL APIs, for consolidation of window-targeting and other docshell mess
• XP embedding APIs (XRE_InitEmbedding) - bootstrapping mainly needs a little glue and a lot of documentation
• Platform-specific embedding APIs
  • ActiveX embedding control - code is there and basically works - needs incorporation into libxul and lots of testing
  • gtkmozembed - code is there and is tested by Epiphany and others: needs incorporation into libxul with some additional glue APIs.
  • The Camino NSView thing: needs help, bsmedberg isn't strong enough in Cocoa to figure out symbol export requirements and linking strategy.

Misc

• evidence-based security model
  • With or without unified security stack tracing?
• roc-style global gc
• XULRunner bootstrapping
  • Stop doing the process restart thing, requires XPCOM shutdown work
  • Provide minimal download CAB for quick initial bootstrap, with additional download in background?
• MathML
• Extension manager enhancements
  • App and Extension locale packs