A lot of the big jump in income is special dividends by companies trying to beat a possible jump in the dividend tax rate from 15% to 43 %.
Although the tax never happened, many companies jumped their dividends to the last part of 2012.
On a personal level, I took about 100K of cap gains in 2012 just in case the cap gains tax jump. This was a one time event for me as I sold stock I held a long time and bought it back the next day (the wash sale rule applies only to losses, not to gains.)
Ding, ding, ding! We have a winner!