Intel's new Sandy Bridge IGP manages to claim the performance leadership of all integrated graphics solutions on the market. It offers nearly twice the performance of its predecessor within the Clarkdale CPU. This means that it can compete with the weakest discrete graphics cards, like HD 5450 or GeForce 210 without any problems. Once you start comparing it to more expensive solutions lke the $60 HD 5550 or GT 430 the performance difference suddenly becomes huge: GT 430 is over 2.5x as fast as Intel HD Graphics 3000 - and it includes support for DirectX 11.
So if you plan on doing lots of desktop work or watching videos with some casual gaming at low resolutions then you should be doing with the new Intel integrated graphics. If you plan on doing any form of serious gaming and don't want to be forced to lowest details settings, then you should go for a discrete graphics card. My suggestion would be to buy a Sandy Bridge model that is cheaper and a bit slower and get a sub-$100 HD 5670 instead of blowing it all on the CPU and then having to wait on graphics rendering all day.
Intel has done a good job with their new IGP when looking at it from a consumer, non-gamer perspective. The new video quality improvement features go hand in hand with support for HDMI 1.4 and accelerated decode and encode. The new hardware accelerated encoding features will come in handy for users who want to transcode their media content into a format suitable for mobile devices.