See this article by Attorney Jay Sekulow for Fox News describing what is known and what will be sought concerning the IRS's mistreatment of tea party groups seeking tax-exempt status. Hat tip to RealClearPolitics for the link.
Echoing Watergate, we need to find out what the President knew and when he knew it. More to the point, did he instigate it or did someone instigate it on his behalf with his knowledge and approval?