Everybody was kung-fu fighting
On TNR.com, Gregg Easterbrook has an insightful article into why special effects don't wow us the way they used to. I think he's largely correct that, for special effects to be truly awesome, there needs to be some suspension of disbelief on the audiences part. Movies like Crouching Tiger, Hidden Dragon use special effects gratuitously, bestowing superpowers on normal people for no good reason (just think how much more amazing old Jackie Chan stunts are by comparison). He also includes some of his trademark "movie physics" analyses. Check it out.