Will Romney be able to stop Taxmageddon?

Not unless he can take office before January 1.

Taxmageddon* is a one-year $494 billion tax increase slated to strike the economy on January 1, 2013. Taxmageddon is made up of several expiring tax policies and the beginning of some major tax increases from Obamacare.

*And they gathered them together to the place which to Hebrew is called Armageddon" (Rev. 16:12-16).

Although these tax increases will not start raising new revenue until next year, they are having a negative impact on the economy today. Families, businesses, and investors need to know how much tax they will pay in the future before making important economic decisions. The uncertainty caused by Taxmageddon means they are stuck in neutral while they wait for President Obama and Congress to act. This is slowing job creation and stopping many of the millions of unemployed Americans from going back to work.

http://www.heritage.org/research/reports/2012/04/taxmageddon-massive-tax-increase-coming-in-2013