When you combine the proposed capital gains rate change of 5.0% with the 3.8% Medicare surtax, this represents an increase of $8,800 per $100,000 of gain for taxpayers with taxable incomes exceeding $250,000 (married filing joint) and $200,000 (single).
That is a 58.7% increase in capital gains tax
You could consider selling a major stock position and paying the tax and then buying the stock back if you believe it is rising or it pays a great dividend. Also, it may be a time to recognize diversification if you have been holding off not wanting to pay taxes. Paying taxes on gains is likely not going to get any cheaper than in 2012 for many years and you have about 13 days to decide!
At my company, we have been diligently working with clients with proactive tax planning all of 2012.