529 plans are of marginal benefit to middle class families. The parents/grandparents who use this as a means to fund college education for their kids/grandkids would be sending their kids/grandkids to college anyway.
No the reason for the move by Pelosi and such to tell Obama to back off is because 529 plans are an awesome way for wealthy peeps to gift large amounts of wealth quickly. Did you realize there is a provision where a person can do 5 years of tax free gifts at once. 5X$14,000, to each and every individual you want to fund double that if there is a grandma.