Wordwiv. What's happening to our language?

So on Monday the 3rd hour class talked about some common English slang terms that came to mind and about the definition of the term slang. As a class we came up with several common themes, among them being that slang terms are society’s response to objects or ideas that need to be put in terms of language, a lingual commonality used within certain communities, and that it is a product of pop culture used to show common knowledge of current events.
All of these definitions have merit, but I was curious to see what people outside of our IB community had to say on the subject. In order to find out I went to one of the places where pop culture, one of the sources that we named as an influence in the development of slang, is compiled from all over the world: youtube.com. What I found is that there are many socially conscious people who are eager to lend a hand to those of us who are uneducated in the language of slang, but even though I picked up some handy new phrases, some of the information in those videos was a little sketch (probably put there by a robocracy), ya know what I’m sayin’ homeslick?
After that experience I went to urbandictionary.com, which describes itself as “a slang dictionary with your definitions” to find out their definition for the word. Like wikipedia.com the information on the website is completely supplied by regular people, but after all I was looking for other people’s definition of “slang”, so it was exactly the type of source I was looking for. Of the two most common definitions (one not having anything to do with language) I found this applicable meaning:

“slang is the continual and ever-changing use and definition of words in informal conversation, often using references as a means of comparison or showing likeness. some modern slang has endured over the decades since its inception (i.e. cool) and some will only last a few years before being rendered obsolete or outdated (i.e. bling bling). slang can be born from any number of situations or ideas, and can be blunt or riddled with metaphor, and often quite profound.

the use of slang is frequently ridiculed by culturally-ignorant people who feel it is the product of insufficient education and believe it to be counter-evolutionary; of course, they couldn't be farther from the truth. human language has been in a state of constant reinvention for centuries, and slang has been used and created by poets and writers of all sorts (William Shakespeare has been credited for the upbringing of at least a couple of words). it is the right and responsibility of the modern human to keep re-evaluating language, to give dead words innovative contemporary meanings or to simply invent new ones, in order to be more appealing and representative to the speaker/listener (which was essentially the basis behind language anyway, to understandably communicate thoughts or ideas verbally).”
-http://www.urbandictionary.com/define.php?term=slang

So my question to all of you is do you agree with this definition that we have a responsibility to revaluate/reinvent language? What purpose does the creation of a new word serve if it will only disappear in a few years, months, weeks?

So don’t be a dandruff, and answer my post!! m’kay.