I would think it would depend on what you define as "core gameplay."  Perhaps you meant to type "as a central theme" in its place.  Indeed many games on HD consoles have excellent physics and can get high marks in that department (or low ones) depending on how it looks.  However most of those games are not completely focused around those physics.  The way a body bounces (or doesn't) in an FPS game is a good example.  It may have excellent ragdoll physics but it's tangential to the focus of the game.  A game like Boomblox for example focuses around physics as a central theme.  It isn't necessarily better than our above FPS example, however it is more pronounced.

That was kind of my point ...

There has been a ton of talk about how the additional processing power of the HD consoles would "crush" the Wii in non-graphical ways in a large part because the extra processing power can be used for core gameplay elements like advanced physics. Yet (with the exception of a handful of games) almost all HD games use their physics engines to create eye-candy and they don't change how a game was played; and in many cases how they use the additional processing power hasn't (substantially) changed the game from those that were made for mid-90s PCs.

The Wii games are far more primitive, and far less impressive, but use the physics in a way which couldn't be done on a system from a decade ago.