I am also afraid that many parents endorse promiscuity at the earliest age possible. It is very sad. We will pay a terrible price for this, even more than we are paying now.
The children led into or forced into an early maturity they cannot handle will pay the greatest price.
My understanding these days is that there is tremendous peer pressure to "perform", and "act" older for BOTH genders of teens. Pop culture continually bludgeons teens with sexual inuendo -- boys are expected to condone and emulate the sexual obsessions of pop stars from M-TV, videos, movies and now even wrestling, and may be derided if they don't join happen to revel in the reindeer games; girls are affected by the above, AND specifically by overtly sexual pop heroes like Britney Spears and her message of "putting out will make you popular."
And sadly, your observation is correct -- younger and younger has become more the rule rather than the exception...