In order to Unicode-enable the PostScript driver, it needs information about about font encodings that isn't present in Adobe's AFM file format (glyph names for character encodings greater than 256). For Type 1 fonts with a standard encoding, the driver can use the encoding in the Adobe Glyph List. (There's no other choice.)
TrueType font designers, however, seem to regard glyph naming as an opportunity to express their creativity. Besides, the information is present in the TrueType font files, so the driver might as well use it.
The driver could read this information directly from the font files, but this would make Wine dependant on the FreeType libraries, and that doesn't strike me as a wonderful idea. Instead, I have cobbled together a small program which reads a TrueType font file and creates a "TrueType Font Metrics" file, which is very similar to an AFM file. (This program does use the FreeType library.)
Anyone have any objections to using this approach as a interim measure?