I personally will sell every stock I own (as will my parents) the day after Obama is elected so that we can pay 20+ years of long term capital gains at the current 15% rate before December 31st.
At 28% I probably wouldn't be as likely to buy back stocks.... might as well just throw it in a CD/MMA/etc with no risk, buy real estate, spend it, etc. The market will also go to shit, so that won't exactly be an incentive to invest either.