The U.S. Senate passed the "Commerce, Justice, Science and Related Agencies Appropriations Act, 2016" as expected; however, the Senate deleted Congressman John Carter's proposed amendment.  That amendment had provided that "SEC.  548. None of the funds made available by this Act may be used to propose or to issue a rule that would change the Chief Law Enforcement Officer certificate requirement  in a manner  that  has  the  same substance  as the  proposed rule published on September 9, 2013 (786 Fed. Reg. 55014)."  Therefore, Rule 41p might still become law.   The ATF has now announced that the date for Rule 41p to be implemented is January 2016.  Further extensions of the date are probable, based on past experience.

Proposed Rule 41p has been in process since September 9, 2013.  The primary focus of the proposed rule is to curb the use of Trusts, and other legal entities, in the "importation, making, exportation, transfer, taxing, identification, registration of, and the dealing in, machine guns, destructive devices, and certain other firearms."  The full text of the proposed Rule 41p can be found HERE.   The Proposed Rule cites this example to support the "need" for the rule:
"ATF recently encountered a situation where an application for a transfer of a silencer was denied because the transferee was determined to be prohibited from possessing an NFA firearm. The transferor subsequently applied to transfer the same silencer to a trust whose name contained the same last name as the prior transferee. ATF reviewed the trust documents and found that the prohibited person was a settlor of the trust and, thus, would have access to the firearm. ATF denied the transfer. However, if the trust name had been different from that of the prior transferee, or if the transferor sought to transfer a different firearm, ATF employees may not have realized that the prior transferee was a settlor of the trust and so may have approved the transfer."
A complete discussion of the proposed rule is beyond the scope of this discussion, therefore, I am addressing the some of the primary points relating specifically to Trusts, so that the reader can get a basic understanding of what is being proposed.  The language in quotes is directly from the proposed rule.  The proposal calls for amendments to the current rules as follows:

1. Amend the definition of "responsible person"  to include any "individual, including any grantor, trustee, [or] beneficiary ... who possesses, directly or indirectly, the power or authority under any trust instrument ... or under state law, to receive, possess, ship, transport, deliver, transfer, or otherwise dispose of a firearm for, or on behalf of, the entity."  The term person would be defined to also include a "trust" as well as each responsible person thereof, as described above.
2. Amend to require that each responsible person of a trust provide:  his or her full name, position, social security number (optional), home address, date and place of birth, and country of citizenship; a photo; and fingerprints.
3. Amend to require each responsible person of a trust to obtain the CLEO statement that the official is satisfied that the fingerprints and photographs are those of the responsible person and that the official has no information indicating that the possession of the firearm by the responsible person would be in violation of state or local law.
4. Finally, under a subsection labelled "Miscellaneous" the proposed rule states:  ATF recognizes that the composition of the responsible persons associated with a trust, partnership, association, company, or corporation may change, and is considering a requirement that new responsible persons submit Form 5320.23 within 30 days of the change.

The Proposed Rule requests comments from the public to the proposed changes.  Enactment of the proposed rule had been delayed and postponed since enactment due to the large number of comments received.  December 1, 2015, has been most recently designated as the enactment date.
However, in June 2015, the U.S. House of Representatives passed H.R. 2578, known as the "Commerce, Justice, Science and Related Agencies Appropriations Act, 2016."  As typical of such acts, amendments are appended that specifically exclude funding for certain specified purposes.  Representative John Carter of Texas offered and the House approved an amendment as follows:   "SEC.  548. None of the funds made available by this Act may be used to propose or to issue a rule that would change the Chief Law Enforcement Officer certificate requirement  in a manner  that  has  the  same substance  as the  proposed rule published on September 9, 2013 (786 Fed. Reg. 55014)."  That House Bill has not yet been acted upon by the U.S. Senate.  If the Senate passes the Bill, and if it is signed into law by the President, 41p could be dead.