Working Capital Express Act of 2010 - Amends the Small Business Act to authorize the Administrator of the Small Business Administration (SBA) to guarantee loans for working capital made by lenders under the SBA's Express Loan Program to small businesses in operation for at least two years. Provides loan terms, including a guarantee limit of $750,000 for each small business.
Directs the Administrator to: (1) establish maximum default and delinquency rates for such loans; and (2) suspend the eligibility to make such loans in the case of any lender with a default or delinquency rate in excess of such rates.