LOL, Oblivion pushes the 360 to it's limits? You realize that Oblivion came out and debuted the same month that the 360 did, right? No way in hell that Oblivion is pushing the 360 to it's limits. Oblivion is just scratching the surface as to what the 360 and PS3 can handle. I don't know where you're reading these pieces of information but, it's wrong.
Well, Oblivion on my ps3 lags near areas like Oblivion gates and it seems to me that Oblivion pushes my ps3 to its limits. I don't believe it is because Oblivion has the best graphical quality available, but because it is poorly optimized, something that is common in all of Bethesda's games. If Oblivion is very easy for my ps3 to handle, then why do I notice lagging, objects appearing out of nowhere, and other occasional graphical errors that seem to support Oblivion requiring a lot of resources? Like I said, I believe it is due to Oblivion being poorly optimized, but how will Bethesda start properly optimizing their games with TES V? They've never been able to do so before.