Main Street Revitalization Act of 2010 - Amends the Internal Revenue Code to: (1) allow small businesses to elect a 10-year carryback of net operation losses incurred in 2010 and 2011; (2) make permanent the increased ($250,000) expensing allowance for depreciable business assets; (3) expand the types of assets eligible for expensing; and (4) increase the tax deduction for business start-up expenditures.