The rules can be found here:
The changes in this final rule take effect on September 16, 2012.
The changes provide a mechanism for assignees to file and prosecute a patent application as the applicant on behalf of the inventor. In addition, juristic entities are required to use a registered patent agent or attorney to take action in a patent application.
35 U.S.C. 115(d)(2) provides that an applicant may provide a substitute statement where an inventor is unable to file the oath or declaration where an individual is under an obligation to assign the invention but has refused to make the oath or declaration required. Therefore, while an assignee may make an application for patent, an oath or declaration (or an assignment containing the required statements) by each inventor is still generally required.