The capital gains tax cuts of Bush contributed to the economic recovery after 2003, perhaps greatly. To some extent, they stimulated saving and investment in productive assets. They brought a degree of real growth driven by entreprenurial activity. These cuts partially rectified the unequal treatment of capital gains for houses (no tax on the first $500,000 of gains.)
These cuts expire at the end of 2010. The Obama administration will not renew these cuts. Both Obama and Summers are on record on that, and both are in accord on opposing capital gains tax cuts as favoring the rich. Pelosi may work toward an earlier expiration. The tax will be restructured in some way, now unknown. The entire process is going to create uncertainty. Higher capital gains taxes as an end result will shock the economy negatively. The powers-that-be seem blissfully unaware of this.
