Linetype definitions haven't changed since r13. I'd like see features like Mtext has like referencing fonts instead of Text Styles and Background mask for the text.
A and S are still the only alignment codes and only A which guarentees the ends always start and end with a dash is documented. Perhaps the more current type formating could be used with a new alighment code.
Expanding ltypeshp to include at least a few arcs would be nice as well.
The abaility to set the text angle without being able to center justify it has always been useless.