There is no asteroid in 2012. The problem is the sun. The sun goes through cycles every 11 years, which is 2012. There will be many solar storms and flares. Scientists have miscalculated the severity of this cycle.This will effect the worlds power grids, but shouldn't kill us.
The next forecasted asteroid hit will be on Easter Sunday, 2036. There's a 1 in 440,000 chance it will hit. The closest odds so far.
So relax! You got a few more years.