"Известие" is also rarely used, usually as a name of a newspaper "Известия". As for "весть", it is still used in some set expressions:
не бог весть что - nothing special
пропавший без вести - missing, as in "missing in action". Literally means "disappeared with no further information"(on what happened to that person or her whereabouts.)
As it often happens, there are derived words still in wide use: извещение, оповещение (notice, notification), повестка ("call-up papers" or "agenda", as in questions to discuss), навестить (to visit).