[From Apple - Mac OS X Leopard - Features - 300+ New Features]
Sure, I purchased Leopard already, even though nothing on this list seems like a 'must-have' feature by itself. I'm hoping the OS architecture will take advantage of multicore chips, and add speed to everyday tasks. Actually, bought the so-called family pack since the number of active computers in my office keeps growing.
Multicore Optimized Take full advantage of modern architectures with multiple processor cores with improved scheduling, memory management, and processor affinity algorithms.
