I think just about every modern TC these days has lockup capability
it's the computer settings that control whether lockup is engaged or not.
Factory settings typically engage lockup once you reach a certain speed/rpm (usually after 3rd gear ,depending on load) to maximize fuel economy under fairly light throttle pressure.
Custom Tuning (like Diablo) can allow lockup earlier by programming the TCM tables for any gear/rpm and even under full throttle.
Even the canned Diablo tunes have advanced lock up over stock for better accelleration performance (racing) as opposed to just better fuel economy (stock)
YouTube on How a Torque Converter works, including "lockup"
(and a couple on auto transmissions)