You are not a citizen until you are sworn in. If you are denied because of failure to pass the English or the civics test, you will be automatically rescheduled within 90 days. If you are not approved for some other reason, you may be given time to overcome the problem.
For 2009, the American Opportunity Credit--which is a variation of the Hope Credit--will be allowed for 4 years. For years before and after the new credit is allowed, the Hope credit is supposed to be for 2 years.
The Hope Scholarship provides a federal income tax credit based on the first $4,000 in postsecondary education expenses paid by the taxpayer during the tax year. The American Recovery and Reinvestment Act of 2009 (P.L. 111-5) included the American Opportunity Tax Credit, which expands the Hope Scholarship.