That's reversing a long term trend of decreasing tobacco use among middle school students. Current usage patterns mean e-sig users tend to go back to tobacco at some point. Thus e-sig's may in fact act like the mythical 'gateway' drug among middle school students.

During 2000--2009, the prevalence of current tobacco use among middle school students declined (15.1% to 8.2%), as did current cigarette use (11.0% to 5.2%) and cigarette smoking experimentation (29.8% to 15.0%)

http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5933a2.htm