Quinebaug and Shetucket Rivers Valley National Heritage Corridor Amendments Act of 2007 - Amends the Quinebaug and Shetucket Rivers Valley National Heritage Corridor Act of 1994 to: (1) extend the authority of the Secretary of the Interior to make grants or provide any assistance under the Act for the Quinebaug and Shetucket Rivers Valley National Heritage Corridor to September 30, 2015; and (2) increase the total amount that may be appropriated for the Corridor.