reinventing ASCII?

Hypothetically, if you could reinvent ASCII in a modern context, what
would you remove or add to the specification?

Unicode looks like its set to take ASCII's place somewhere down the
line, so this is mostly a thought problem, but I'm curious about what
changes others might implement. I think the first logical change would
be implementing it as 8-bit, rather than 7-bit, to take advantage of a
full byte. After that, maybe remove most of the non-printable
characters. I don't know any modern programs that take advantage of
most of them. What to fill the additional spaces with though, I don't
know.