Languages change over time, which is why you shouldn’t take seriously any claims about this language being older than the other, or vice versa. A language is only old in the same sense that a farmer can say, “I’ve had this axe for years. I’ve only changed the handle twice and the head three times.”
Language change is probably slowed these days by stasis-inducing factors like books. However, rapid communication means that new phrases or ways of speaking can be disseminated with lightning speed. Here is an interesting article about the effect McCain & Palin’s drill, baby, drill has had on the English language.
A Bush-administration flunkee’s unfortunate statement that reporters — but not members of the Bush administration — are members of “what we call the reality-based community” led to an interesting shift in the way Progressives speak. The compound adjective “reality-based” has become part inside joke, and part simply a new word. I suspect “real America” will similarly entrench itself in the English language.