[Jimbee (OP)]

What exactly is the linguistic status of the word "thrice" now? Words are acceptable. Then they become archaic. Then they are obsolete. It's obviously not obsolete yet. But is it archaic?

In the US, where I live, it's used more in an ironic or humorous sense. People rarely use it otherwise. What's it like in other English-speaking countries? Because I would argue it is archaic. But Webster's New World Dictionary claims it is not yet.

[evan_au]

"Once" and "Twice" seems to be alive and well, where I live (Australia).
"Thrice" seems to be endangered.

[alancalverd]

There are definitely two forms of English in any Anglophone country: impotent quotidien prose (now castrated by Act of Parliament), and the rich magical thunder of the King James Bible. "Thrice" was good enough for Shakespeare. 

Use it or lose  it!

[Bored chemist]

and the rich magical thunder of the King James Bible

... castrated when people realised that magic doesn't work.
I still use thrice. It's a perfectly cromulent word.