In a short answer? Yes. Quite often, people who are "worried about what will happen in 2012" say one thing that might happen is the reversal of the Sun's magnetic poles, presumably leading to some kind of havoc here on Earth.
In reality, the Sun's magnetic poles naturally reverse direction every 11 years. The magnetic field of the Sun is due to what is referred to as the "magnetic dynamo effect". Whenever electrical charges (such as protons) move, they make a magnetic field. The Sun's interior is composed mostly of ionized Hydrogen (meaning its electrons have been removed, and only a proton remains). When these protons get "pushed outward" from the center of the Sun toward the outside, they make a magnetic field. The currents from these protons make a series of small magnetic fields around the interior of the Sun. The magnetic fields lead to sunspots, which are areas on the Sun that are darker than the surrounding surface.
It's not exactly clear, from a scientific point of view, why the Sun's magnetic field reverses direction. However, a likely hypothesis is the "Babcock model", which says that the field lines from sunspots get tangled up over time. This provides a type of "pressure" on the material, until eventually the protons' motions that make up the Sun's magnetic field change direction.
Sunspots also produce solar flares, which are bursts of light at all wavelengths. These flares can also produce streams of particles that move at a very high speed (called a Coronal Mass Ejection). The more sunspots there are on the Sun, the more solar flares and Coronal Mass Ejections there will be. The time of highest sunspot activity is immediately before a reversal in the Sun's magnetic field. Therefore, 2012 will be a year with a high number of solar flares. Unfortunately, solar flares can strike the Earth's ionosphere, and disrupt long-range radio signals. Further, flares can be hazardous to the electronics systems of satellites. This being the case, people on Earth have to be extra prepared for these cycles and their implications in an increasingly technological world.
So while it is true that the Sun's magnetic field will reverse direction in the year 2012, the claims of people about this phenomenon being dangerous to the Earth are overblown and exaggerated. Careful preparation for the possible disruption of radio communication is warranted, but magnetic pole reversals of the Sun are certainly not destructive to the human race.