A fourth TimeSplitters may still yet see the light of day if rumours are to be believed. In the latest issue of OPM, the rumour segment lists TimeSplitters 4 as "to be announced soon."
"Gun-wielding monkeys are finally making a comeback! A fourth Timesplitters title is to be announced soon," claims the publication.
The last TimeSplitters game was released back in 2005 on PS2, Xbox and GameCube. That seems like such a long time ago.