Oct. 2003: Current version is 1.0, which fixes a variety of minor bugs. The important changes are below. A detailed description of changes is available here.
June 2003: We recently published a paper in WDDD 2003 using HotLeakage to compare state-preserving (eg, drowsy cache) and non-state-preserving (eg, gated-Vdd/gated-Vss) leakage control, and found that even though gated-Vss loses state when it puts a cache line to sleep, it can still be superior as long as L2 latencies are reasonably short, like might be seen with an L2 cache. The paper can be found here.