The only trouble with the America Invents Act of 2011 is it is not an Amendment to the Constitution, which it needs to be in order to change the original text of the Constitution which clearly specifies (re: "Inventors") the "first to invent" system over the "first to file" system.
No it doesn't. It specifies that the rights over their discoveries shall go to the Inventors but it nowhere specifies the process that inventors shall be required to undergo to secure those rights.
Under first-to-file as it is practiced elsewhere it is still illegal for anyone other than the inventor to secure a patent on a discovery. It is really a very minor change which only makes a difference in the case of near-contemporaneous discoveries. It mostly benefits accidental inventors who are less likely to be able to provide any evidence for the date of invention than the industrial-scale patent-generators who receive most patents.
A secondary effect which may turn out to be rather more important is that the current US system requires that you file within 1 year of the discovery or never file for patent protection; so an invention cannot be kept a trade-secret and used for 40 years before being patented by that same person/corporation when they feel there is a risk of someone else working it out, effectively securing them a 65-year monopoly. First-to-file elsewhere generally allows this; I am not familiar with the US statute in question.