Unless Congress takes action, the top tax rate for the highest earners on most dividends, currently 15%, is set to jump to a whopping 43.4% next year. That is a maximum income-tax rate of 39.6% -- since dividends will once again be taxed as regular income -- plus a 3.8% tax on investment income as part of the health-care overhaul passed in 2009.

Higher dividend taxes could take some luster off dividend-paying stocks -- and because the market is forward-looking, the fear is that their prices will fall sooner rather than later.