Deep CoverDavid Byron sent me more information on the long-lost Looking Glass espionage game:
The unannounced game Looking Glass Studios was developing was called "Deep Cover", and it was set in various locales during the cold war. You can find screenshots of the roughed out levels (and the names/themes of the levels) here and there on the web. Here's an example: Deep Cover (lefthand menu leads to screens).
Those are screenshots of a game I would have definitely wanted to play.
He also mentioned that some of the developers shared quite a bit of information about the game on the Looking Glass forums at one time.