'whole nuther'

Perfectly wonderful in speech and informal settings (such as online forums), probably wouldn't use it in formal written texts, unless jocularly.

Or something that should be vigorously discouraged, vehemently disallowed, officially indexed and banned?

Ain't gonna happen in my lifetime. Sometime in the inchoate future it may go the way of other linguistic dodo birds.

Ceci n'est pas un seing.