Actually, changes like this tend not to be one thing turning on and only one thing happening, but a viable change is when one thing turns on and - since other portions are already in go position - the entire regulatory chain kicks in.
Be careful, though. Turning on things can have interesting side effects. Like cell bleeding, biochemical imbalances, etc.
PZ Myers gave a good talk about non-coding DNA. Short version: most of it really is junk. 5% is functional (genes, useful RNAs, regulatory regions), 10% is structural (centromeres and telomeres), 45% is parasitic (LINEs, SINEs, endogenous retroviruses, transposons), and the remaining 40% is probably pure garbage.
Be careful, though. Turning on things can have interesting side effects. Like cell bleeding, biochemical imbalances, etc.