1. A method of generating object lifetime statistics based on run-time observations, the method comprising: selecting from amongst object instances of an observed category, a sampled subset of the object instances allocated in one or more execution threads of a computational system; coincident with allocation of a sampled instance of an object, establishing a weak reference thereto and associating therewith information indicative of at least allocation time; and referencing the sampled instances at run-time via the weak references and updating the object lifetime statistics based on the associated allocation time and then-current state.