Treyarch's game design director, David Vondehaar, has become a bit frustrated at the hate the Call of Duty Infinity Ward Engine has been receiving over the years. At this point, he goes on to defend the engine for having new lighting, shaders and an overhaul to to the gun mechanics, which he believes is still top notch.
In a brief snippet from an interview with the Official Xbox Magazine regarding Call of Duty: Black Ops 2, Vondehaar stated that...
"Anybody who comes at the engine needs to remember it's the 60 frames they love in the first place," ... "And we can make it beautiful - that's through years and years of working with the engine, improving upon it and improving the pipeline and improving our approach, our lighting rendering.
Let's be honest here: it doesn't matter what Treyarch or Infinity Ward does at this point because most of the changes to the engine itself are under-the-hood changes that gamers will rarely notice while actually playing. What's more is that there's nothing else that can really be done with the game(s) than what's been done. So we're basically seeing slight changes here and there for annual outings for something that's already pretty much peaked.
We're also at the end of a generation and I'm sure we'll see another Call of Duty for the Xbox 360 and PS3 in 2013 before Activision decides to upgrade the series over to the new consoles in 2014. This means that next year's outing from Infinity Ward will just be some more minor tweaks and modifications on what could already be considered a perfected engine for today's generation of consoles.
While EA receives a ton of flak, I at least have to give them props for getting behind Battlefield 3 to introduce something slightly different than what we've been receiving from shooters, that's not to mention that it was a big step in a different direction from what we received with the Bad Company series, so the engine didn't feel worn out and terribly rote, which is kind of what happened to Call of Duty.
Most gamers just kind of feel that the series has diverged into glorified-expansion territory. And while I agree with Vondehaar that given the limitation of today's console hardware we can't expect much more from an engine than what we're receiving in terms of maintaining a certain level of graphics fidelity while also maintaining the kind of gameplay that it does, it doesn't mean the devs have to keep graphics a priority if they really wanted to explore new gameplay elements.
Nevertheless, while gamers can't expect much more from what Activision can squeeze out of consoles using the tech that they're using, it doesn't mean gamers have to sit around and acquiesce to the repetitive outings.