When I originally started with D, I thought non-ASCII identifiers with Unicode
was a good idea. I've since slowly become less and less enthusiastic about it.
First off, D source text simply must (and does) fully support Unicode in
comments, characters, and string literals. That's not an issue.
But identifiers? I haven't seen hardly any use of non-ascii identifiers in C,
C++, or D. In fact, I've seen zero use of it outside of test cases. I don't see
much point in expanding the support of it. If people use such identifiers, the
result would most likely be annoyance rather than illumination when people who
don't know that language have to work on the code.
Extending it further will also cause problems for all the tools that work with D
object code, like debuggers, disassemblers, linkers, filesystems, etc.
Absent a much more compelling rationale for it, I'd say no.