Arizona's new Immigration Law: fact or fiction?

The governor of Arizona has just signed into law a bill giving police the right to stop and question suspected illegal immigrants that appear to be in the United States illegaly. opponents of the law state this will lead to racial profiling and violations of discrimination in that state. the governor states the Federal Government is not enforcing the illegal immigration laws, so its time for her state to more or less protect itself. Obama states this new law undermines Federal Law. several questions here: is the governor of Arizona correct? are her actions correct in order to protect her state from inactions by the Federal Government, concerning illegal immigrants enforcement? Federal Law is the law of the land. Will the governors new Immigration Law for Arizona be superseded by Federal Law? this should be an interesting case to follow for Arizona and the rest of the country. whats your opinion?