The Department of State announced that it will be publishing a rule to de-link visa validity with petition validity for L-1 visa applicants. What does this mean?
Usually the visa end date is the same as the petition end date. The petition is what is filed with the Immigration Service to provide initial approval for visa issuance at a U.S. Consulate. This is most often a petition specifically for the beneficiary applying for the visa, but "blanket L" petitions are also available in some situations. A Blanket L petition can be used by an unlimited number of visa applicants.
An example to show this point is: Mary is approved for a change of status to L when she is in the U.S. In 2010. She does not travel outside the U.S. Until 2012. The petition end date is in 2013. The L visa can be issued only to 2013 as the rule now stands.
Once the rule is changed, the end date of the visa would not be limited in this example to 2013. Instead the consular officer would look at the visa reciprocity schedule for Mary's home country.
If she is from China, which allows L visas for two years, the visa could be issued to 2014 in this example. If she is from India, which allows L-1 visas for 5 years, the visa could be issued to 2017 (if it is an L-1A or 2015 if it is an L-1B - because of the limit on total L status duration).
Whether this change is helpful thus depends on the reciprocity schedule of the home country. It will likely be most helpful with Blanket Ls close to the petition expiration date (the first Blanket L is granted for only three years, but the extension is indefinite) and for visa applications closely preceding an extension filing.
The effective date of the rule has not been announced.