Applicants have been rushing to file under the old system that was more favorable to applicants. I've had some rushes myself. I suspect that the companies that spent small fortunes lobbying for these changes were some of the companies that were rushing to file under the old system.
The definition of prior art is expanded under the new system and can even include oral disclosures, as well as a lot more foreign prior art. Here is the new 35 U.S.C. 102:
(a) Novelty; Prior Art.— A person shall be entitled to a patent unless—
The definition of prior art has been changed to be measured from the effective filing date versus from the invention date. The longer an applicant waits to file, the more potential prior art there will be.
In addition, things that were in public use or on sale in foreign countries have been added to the pool of prior art. Anything otherwise available to the public anywhere in the world is also added to the pool of prior art. This could include oral disclosures.
It will take the courts years to more clearly define some of these terms. For example, it is unclear whether a secret sale would be considered to be prior art. If a third party publishes something similar to but different from an inventor's publication, an expensive derivation proceeding may be required to prove the prior art disclosure was derived from the applicant’s claimed invention.
A U.S. patent or published U.S. or PCT application becomes available as prior art on date that the U.S. patent or published application is “effectively filed.” The date that a U.S. patent or U.S. or PCT published application is “effectively filed” is the earlier of: (i) the actual filing date of the U.S. patent or U.S. or PCT published application; or (ii) the filing date of the earliest application to which the U.S. patent or U.S. or PCT published application is entitled to claim a right of foreign priority or domestic benefit which describes the subject matter.
A Japanese patent application publication has a prior art effect under AIA 35 U.S.C. 102(a)(1) as of its publication date. Prior art under 35 U.S.C. 102(a)(2), which becomes available as the basis for a rejection as of the date that it was “effectively filed,” is limited to U.S. patents, U.S patent application publications, and published PCT applications which designate the United States.
Interferences will no longer be required with the first-to-file system, but instead there will be "derivation proceedings."
A derivation proceeding requires that an applicant for patent file a petition to institute the proceeding. The petition must set forth with particularity the basis for finding that an inventor named in an earlier application derived the claimed invention from the petitioner. The petition must be made under oath and supported by substantial evidence. The petition must be filed within 1 year of the date of the first publication of a claim to an invention that is the same or substantially the same as the earlier application’s claim to the invention.
It is best not rely on the supposed one year exception or grace period of part (b) and instead to maintain absolute novelty until after a patent application is filed.
Consider this fact pattern: You make a new invention and start selling a product that embodies that invention. Relying on the grace period, almost a year after you started selling, you ask your patent attorney to prepare and file a patent application for you. The application is filed almost a year after your first sale. However, 6 months after you starting selling your product, a competitor filed a patent application covering it. You correctly suspect that they copied your idea. However, their application gets cited against your application during prosecution. What can you do when you receive this rejection? Derivation proceeding you say? The requirements for initiating a derivation proceeding include demonstrating that an invention was derived from an inventor named in the petitioner’s application and, without authorization, the earliest application claiming such invention was filed; and submission of substantial evidence, including at least one affidavit addressing communication of the derived invention and lack of authorization that, if unrebutted, would support a determination of derivation. The showing of communication must be corroborated. What evidence do you have? True, they are not an inventor and should not be able to obtain a valid patent, but will you be able to obtain a patent?
This is why I recommend not relying on the one year limited grace period.