Virtual VCS
Developer: Temporary Sanity Designs
Publisher: Atari
State of completion: EPROM prototype exists, Carl Forhan's Songbird productions may finish and release this program.
Genre: Atari 2600 Emulator
Also planned or released for:  
Screenshots, Pictures: vcsadv.jpg (13122 bytes)  vcscombt.jpg (14675 bytes)  vcspman.jpg (31254 bytes)  vcsyar.jpg (14817 bytes)

These are screenshots of the actual program running off the EPROM prototype (courtesy of the original owner before it was auctioned off on Ebay).
Left to right: Adventure, Combat, Pac-Man and Yar's Revenge.

(video from actual game, thanks Carl!)