Probably not - it's doing something far more important than that.
It's already been known for a few years now that the "junk" scales directly with complexity of the organism - unlike number of genes, which does not. It's becoming increasingly apparent that huge numbers of "junk" sections of DNA are actually transcribed to RNA, and play essential roles in regulating what gets made into protein.
The new hypothesis is that RNA is the computational engine of the cell, allowing it to rapidly process information and react appropriately, and the non-protein-coding "junk" sections are what it uses to do this.
There's a guy called John Mattick from the University of Queensland who has done a lot of really exciting work in this area, and gives a fantastic talk on the subject - here's an abstract for a version of it. Sample quote:
the extent of non-protein-coding DNA increases with increasing complexity, reaching 98.8% in humans, suggesting that much of the information required to program development may reside in these sequences. Moreover it is now evident the majority of the mammalian genome is transcribed, mainly into non-protein-coding RNAs (ncRNAs), and that there are tens if not hundreds of thousands of long and short RNAs in mammals that show specific expression patterns and subcellular locations. Our studies indicate that these RNAs form a massive hidden network of regulatory information that regulates epigenetic processes and directs the precise patterns of gene expression during growth and development.
Using the argument that cells are RNA machines, there is most likely no junk whatsoever in the human genome.