The inflection point for diminishing returns appears to be the PS3/360 generation

[theRepublic]

Zappykins said:
Well, look back at gens 3-4-5. Sure it changed, but not all that much. The last gen was a HUGE change. Consoles made huge graphic leaps last gen. Now it's slowed down again.

Also look at the start of last gen, verses how things look now. Crackdown and Oblivion are nice, but check out Halo 4 or Skyrim. Nice gains there too. Hopefully this gen will really look even better in a year or two.

What?  I would argue the exact opposite.  There were massive differences between those gens, easily visable to even the most casual observer.  From 4 to 5 we went from 2D to 3D.  That is a much bigger change than what we saw last gen.  I posted pictures earlier in the thread.  The differences are becoming smaller and smaller as we go.