According to FactCheck.ORG: President Obama graduated from Harvard Law School in 1991 and was admitted as a lawyer by the Supreme Court of Illinois on Dec. 17, 1991. Prior to being elected to the Illinois state Senate in 1996, he worked as a civil rights lawyer at the firm formerly known as Davis, Miner, Barnhill & Galland. Four days after Obama announced that he would run for president in February 2007, he voluntarily elected to have his law license placed on “inactive” status, according to Grogan. Then, after becoming president, he elected to change his status to “retired” in February 2009. Michelle Obama graduated from Harvard Law School in 1988, and was admitted as a lawyer by the Supreme Court of Illinois on May 12, 1989. Following graduation, she joined Sidley Austin, a corporate law firm in Chicago. But a few years later, in 1994, while working for the Public Allies project in Chicago, Obama voluntarily had her license placed on “inactive” status.
Thanks for the link. FactCheck does, in fact, confirm that their law licenses are inactive (or, in Barack's case, retired), but it goes on to say:
"But the claim that the Obamas “surrendered” their licenses to avoid ethics charges has no basis in fact. Neither of the Obamas has any public record of discipline or pending proceedings against them, according to the online public registration records of the ARDC. We also confirmed that with Grogan, who said that the Obamas were "never the subject of any public disciplinary proceedings."
Which is directly opposed to one some others have said on this thread, that the Obamas gave up their licenses to prevent some sort of charges or ethics complaints from being pursued.