Both the PS3 and XBox 360 are (or already have) reached the hard-limits on what can be achieved on their console from a technical perspective; this means you will probably not see any games that have higher polygon counts, or more complicated shaders, or that have a greater quantity of texture data. This is not unlike the position the previous generation consoles were in at the end of 2003.
From this point forward, developers will be working within these limits to try to get the maximum impact from the performance they have achieved by minimizing the waste ... Many of the "Best Looking" HD games so far, have had a lot of wasted performance from polygons being rendered which do not add anything to the scene or texture/lighting effects which are not as efficient as they could be.
