System Shock/WMG

System Shock and BioShock (series) take place in the same continuity.

 * Fontaine, Ryan, and any other characters that will be in BioShock (series) 2 influenced the creation of SHODAN.
 * Maybe we can expect a Grand Finale for the entire franchise.

System Shock and Dead Space take place in the same continuity.

 * As mentioned in the main page, Dead Space is thought to have originally been developed as System Shock 3, so there's lots of similarities. Way farther into the future after System Shock 2, the Marker was created and placed on Tau Ceti to keep The Many contained on the planet, but it was eventually forgotten until the events of Dead Space. In that time The Many had evolved further into the Necromorphs that we all know and fear today.

The Hacker is a Eldritch Abomination in human form
It explains why he can interact with objects 13 feet away,can be rebuilt after enduring things no man could survive,doesnt mutate,can subside only on patches and batteries and you cant see his legs due to the fact hes hovering (with running actually being propelling himself throught the air).

SHODAN and GLaDOS regularly see each other.
Come on...you know it would be cool.