Most games use in-engine cinematics for stuff like conversations between characters anyway. There they can unload a lot of gameplay related data and up the texture resolution, shader quality and poly counts a lot.
This has absolutely no relation to what the engine can do within the gameplay, it's more about whether the studio wants to spend extra work and money on content specific for these cinematics.
In-game story sequences are a different issue, for example as in Half-life games, where they can't stop and throw out player weapon models and such from memory and so the resources are more constrained. But I'm nut sure how many of these Crysis 2 is going to have, so it's still not that interesting to compare MP character faces with, say, Uncharted 2.
This has absolutely no relation to what the engine can do within the gameplay, it's more about whether the studio wants to spend extra work and money on content specific for these cinematics.
In-game story sequences are a different issue, for example as in Half-life games, where they can't stop and throw out player weapon models and such from memory and so the resources are more constrained. But I'm nut sure how many of these Crysis 2 is going to have, so it's still not that interesting to compare MP character faces with, say, Uncharted 2.