Planetary alignments and galactic alignments? No special planetary alignment occurs this year. Every year at the time of the Winter Solstice, the same alignment occurs, and nothing has happened. Back in December, 2004, there was an alignment such that in the early morning, Mercury was near the Eastern horizon, Venus was a bit above that, then Mars, Jupiter and Saturn each higher than the previous across the zodiac. With all these planets on the same side of the Earth-Sun line, nothing happened.
The 11 year solar activity cycle is expected to peak sometime around mid-2013. This cycle has been going on (probably) forever, and sunspots were first observed by Galileo in the 1500s. This solar maximum is not expected to be as big as those back in the late 1950s and the one in the late 1960s.
There are no known comets or asteroids or other objects expected to impact the Earth in the future, but astronomers continue to search, observe and calculate orbits to monitor any objects which are likely to collide with Earth.
Same kind of discussion applies about any other "reason" for it.
Given all the above, I recommend the following:
1. Don't run up your credit cards and other debts expecting that you won't have to pay them back after December 2012.
2. Don't skimp on your studies because you thought that by the end of 2012 it won't matter!
3. Remember that "I read on the internet that the world was going to end, so I didn't buy any Christmas presents" will sound really lame on Christmas morning.
4. This list could continue indefinitely...