PS3 and Xbox360 look more or less the same.
Xbox360 does 4xAA standard. Polygon culling is a rendering technique not exclusive to the PS3. The same goes for light rendering and post processing.
Killzone is not available on Xbox360. Try comparing apples to apples.
Xenon does all the above, yes.
360 does not do 4xMSAA standard, The option is there but due to a 720p frame buffer with 4xMSAA requireing 30mb of memory developers don't use it because you can't fit it straight into 360's 10mb EDRAM, So you have to tile rendering which is not a viable option as
1. It requires an engine that's been built with tileing in mind, And because most engines are multi platform it's easier for developers to not use tiling and make porting easier.
2. Tlieing has down falls of it's own
3. The EDRAM is the reason why most 360 games run at less then 720p, It's also the reason why Halo 3 only runs at 600p because a native 720p buffer would not fit into the 10mb EDRAM. Develoers run a smaller resolution buffer which then alows them to run anti-aliasing while still being with the 10mb EDRAM limitation.
Polygone culling is not PS3 exclusive but RSX is not particually good at it, It also consumes RSX's time and Cell is better at it and has enough spare cycles to do it so why do it on RSX and waste performance and time?
Again the same with light rendering, RSX can only do so much, Any work which Cell can handle get's shifted over to Cell leaving RSX free to handle the heavier tasks. Why do you think PS3 game have got a lot better over the last 12 months? Because developers are having Cell do all the donkey work. Why have RSX doing morhological anti-aliasing and other compute heavy work loads when Cell can do it faster thus freeing up RSX do to somthing else?
And no Xenon can do fuck all in terms of rendering, You never hear any developer saying they're calculating MLLAA, global illumination, culling or anything else for that matter on Xenon, You know why? Because it just doesn't have the spare power to do it. If xenon had enough spare resources to handle and take some of the work load off Xenos leaving it free to do other things then developers would take advantage of that but they don't because Xenon can't do it.
And delveopers have stated multiple times that PS3 has the edge when it comes to CPU power so it's a good job xenon isn't inside PS3 because it would slow the whole system down.
And for the record they don't look the same, PS3 exclusive games look a hell of a lot better then 360 exclusive ones do now.