I assume you're talking to me - At the time Ion Storm was bleeding Eidos dry, Looking Glass was in a bit of a tight spot because Thief 2 wasn't selling as much as they hoped. IF Edios wasn't busy bailing out Romero's hairy arse, they may've been able to float LGS the cash necessary to continue on, but because Romero's ego needed so much funding, LGS starved to death. (Some apologists for JR try to deny that LGS was his fault, but they're kidding themselves.)
Fortunately, a bunch of the LGS crew landed at Ion Storm-Austin (now called Ion Storm) and Thief 3 is in the works under the oversight of Warren Spector and the GROWN-UPS at his place.