For the record, there was a guy that was actually working on emulating these games by literally emulating every single electrical circuit on the board.
As you can imagine though, this made for a lot of overhead. The emulator wouldn't even run more then a few fps on the fastest of machines.
With that being said, the guy who wrote it didn't know much about programming or game design, just electronics.
If someone with good programming experience could get ahold of an original pong schematic and actually understand what it means, then true discrete logic emulation at a playable speed would be possible.
There has to be someone out there with such skills..... afterall you can build a pong kit in under a day so there couldnl't be a lot to it.