Thanks to James O'Leary ( http://musicasacra.com/forum/discussion/5849/ ), we know that the "Revised Grail" Psalms will not be inserted into the Lectionary until said Lectionary is revised, according to the Secretariat:

Date: Fri, Nov 11, 2011 at 9:24 AM
There is no plan to do a major revision of the Lectionary at this time. There are some minor adjustments that will be made to the Lectionary texts, but those will not result in anything more than a reprint of the current edition, and parishes will only need to purchase them when they are ready to replace worn-out volumes, which happens with all liturgical books at some time.
Signed,
Msgr. Rick Hilgartner, Executive Director, Secretariat of Divine Worship

I wanted further clarification, so I wrote (Monday, March 12, 2012 at 12:31PM)

Dear Monsignor,
When the new revised Grail begins to be printed in Catholic Lectionaries (whenever that may be), will the musical settings with the NAB still be allowed, or does their approval "expire" ?

Response was received (Friday, March 16, 2012 at 9:10AM)

This will be a “gray area” until all ritual books are revised to include the Grail. As long as there are any approved books with the NAB Psalter, it will be an approved text. That could be 20 more years…

Msgr. Rick Hilgartner
Executive Director
Secretariat of Divine Worship
United States Conference of Catholic Bishops
3211 4th St. NE
Washington, DC 20017
voice: (202) 541-3060
fax: (202) 541-3088

Tags: New Catholic Lectionary, New Translation of the Lectionary, Catholic Mass, NAB, Revised Grail Translation, Psalter, Psalms