Announced in late 2014, FSA will be replacing the PINs that students and parents have used to sign in to complete the FAFSA, MPN, and other financial aid forms. This change is supposed to officially take place on April 26, 2015.
If you sign in to any FSA site (including StudentAid.gov, FAFSA on the Web, StudentLoans.gov, NSLDS student access, etc.) after that date, then you will be redirected to a new FSA ID page. On this page, you will be directed to pick a username and password for sign in purposes, but just like with the PIN, you will have to wait 1-3 days for the Social Security Administration to verify for identity. (Currently, you are allowed a "conditional PIN" for the 1-3 days in order to complete the verification process.)
Students who already have a PIN will be given an option to link their PIN to their new FSA ID. This will allow them to use their new FSA ID with full functionality without having to wait the 1-3 days on a conditional basis. Also, this will be much quicker of a process since completing application of a new FSA ID is estimated to take about seven minutes.
In mid-April, there is expected to be a new page on StudentAid.gov with more information about the transition, so keep on the lookout for it.