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.
These income limits are higher than under the existing Hope and Lifetime Learning Credits. The AOTC applied to tax years 2009 and 2010 under ARRA. The credit was extended to apply for tax years 2011 and 2012 by the Tax Relief and Job Creation Act of 2010. The American Taxpayer Relief Act of 2012 extended the AOTC for five years through December 2017.