-Utterly inadequate for gaming.
-Uses up valuable space inside the CPU Intel should have used for more transistors or something. Seriously, who buys a 3570k with the intention of using integrated graphics?
Pro: It comes free when you buy the i5-3570k or i7-3770k. Or any laptop with an Ivy Bridge CPU.
Con: Cannot play games very well. It is about as powerful as a Radeon HD 5550. You can play games at low resolution (1366x768 or less) with a mix of medium and low settings for non-graphic intensive games like Mass Effect trilogy, Half-Life 2 and Fallout 3. However for moderately graphic intensive games you need to play with low graphic settings. Intensively graphic games like Metro 2033 should be avoided.