If you though that after dual-chip cards the rest of 2011 will get very boring for the graphics world, you got it right. After Radeon HD 6990 and GTX 590 we can only wait for 28nm chips and hope that they will make a real difference. Turks and Caicos will barely excite anyone as the Llano APU will have graphics that will put a lot of pressure on mainstream market. Brazos will compete with entry level.
According to our sources, AMD's Southern Islands are nothing more than a die shrink of an existing 40nm Northern Islands. There won't be any major architectural difference, just a die shrink. However, you can expect to see some more shaders, as at 28nm there is simply more space and the TDP's are lower. This still means that the chips that will replace the HD 6870 and HD 6850 will get more shaders and performance.
The new graphics architecture from AMD will only come in 2012, when the 28nm process gets more mature, and most likely this will happen only in second half of the year. Whether you like it or not, you will have to start getting excited about integrated graphics as from this point there will be more and more graphics on CPUs.