I like the idea of things just starting to get more public. The Secret World has always existed, but thus far it's been "contained." Perhaps with 2012 approaching (I know it's a cliche), the balance has swayed and now more and more things are appearing in the mortal spectrum, whereas before they rarely ever did.
Every legend, every myth, horror story, they are all based in reality. At different points in history, the balance would sway in very centralized areas allowing things to pass into the mortal spectrum briefly long enough to be witnessed / experienced by humans. The eye-witness tales of those tumultuous times were passed down from one generation to the next until eventually they became fairytales, myths / urban legends.
I picture the swaying of balance as being something like the opening of a rift, or lifting of a veil. Sometimes things have been able to slip through and remain, but rarely. In the past, these "rifts" were closed by members of secret organizations such as the Templars, Dragons, and Illuminati, and nearly everything that ever escaped a "hot zone" was hunted down by said organizations.
Now the rifts are opening too widely / too often. Things are entering the mortal world at such a rapid rate, in such large quantities, over so vast a number of areas they can no longer be contained. The conspiracy theories and legends are rapidly proving true to more and more people. Now, instead of an elite few fighting the darkness / maintaining the balance, the whole world is about to be recruited into the "war." Those who cannot adapt, the weak, they will die. Those who remain will have no choice but to become soldiers in a bleak, seemingly neverending war.
There could be more than just the 3 secret societies listed on the Secret World site (Illumunati, Dragon, Templars). There could also be non human members recruited into the societies, or there could be non human societies striving for the good of humanity whilst being attacked / hunted by purist human groups that feel nothing from outside the mortal realm should be allowed to exist / remain within it.
There could also be dark human / non human cabals, determined to bring the things from beyond into the mortal realm. Their ultimate goal is to see the veil forever torn / chaos ensue. Perhaps that side is winning now. I see the ancient Aztec worshipers of Huitzilopochtli as an example of one such (now defunct) cabal.
As an aside, I imagined my character waking up not only with amnesia, but also discovering she had what looked to be cesarian scars. At some point in time, she has had a baby. What has happened to that baby? Who is the father? Why does she no longer have the child with her? Was the child stillborn? Etc...