In a nutshell, the test showed a 10% performance increase over today's similarly-clocked processors without consuming more power. More impressively, the integrated graphics outpaced a discrete ATI Radeon HD 5450 by a respectable margin in many benchmarks, showing playable frame rates on some recent games like Dragon Age: Origins, Modern Warfare 2, and BioShock 2 -- albeit on lower-quality settings.
Sadly, Intel plans to complicate the process of overclocking (again). The company will sell most mainstream Sandy Bridge processors with locked (or "partially unlocked") multipliers. Overclockers will have to purchase K-series products, which will be unlocked at a premium price. Be sure to read Anand's exhaustive 13-page preview here.