Is cc still a valid abbreviation in the computer/printer age?
"Blind carbon copy" (bcc) is also still used.
I have encountered a few people from some secretarial schools in North America who are taught to use the word "copy" at the bottom of letters, rather than "cc"; apparently the logic stems from the fact that if printed on a printer, the letter (or document) is not strictly a "carbon" copy, but rather just a second printing. So, that makes it a "copy" only.
It's reasonable -- but certainly "cc" is still accepted, and used widely.