The America Invents Act was signed September 16, 2011 and became effective September 26, 2011.  It concludes a six-year effort to make reforms to U. S. patent law.  While the reforms are many and some fundamental, the initial impact is an increase in fees paid to the PTO by patent applicants and patent owners. 

The Act will change the nature of patent practice, for patent applicants, patent owners and patent attorneys.  The interference practice unique to U. S. patent law will be abolished in favor of a derivation contest.  The U.S. will convert to a first-to-file system, necessitating the prompt filing of patent applications.  Patents will be subject to post-grant challenges, much like oppositions, conducted by the PTO.  Fortunately these changes, with the exception of increased fees, will be implemented over time. The PTO has created a site http://www.uspto.gov/aia_implementation/index.jsp to provide information about implementation of the Act.