* Text support. Glyph set management, glyph and string compositing
  operations. Some ideas: Multi-texturing for compositing multiple glyphs 
  per render pass, Sub-pixel rendering, vector text; glyphs loaded into 
  display lists.

* A programmable surface type which can store a set of rendering operations
  in a display list.

* Projective transformations.

* WGL (Windows GL) backend.
