On May 10, the Vermont legislature passed Senate Bill 86, the omnibus election law bill. It moves the petition deadline for independent candidates, and the nominees of unqualified parties, from June, to August. The presidential petition will always be due August 1. The deadline for independent and minor party candidates for other office will be five days before the primary. In 2014, that deadline will be August 7, and the primary will be August 12.
Assuming the Governor signs the bill, the only states that have an independent presidential petition deadline earlier than July are Illinois, New Mexico, North Carolina, and Texas. Illinois, New Mexico, and North Carolina have June deadlines. The Texas statutory deadline is not settled, and is entangled with various lawsuits on redistricting which also affect primary dates.
The Vermont bill also moves the primary from late August to mid-August. It takes effect immediately.
In Texas, voters who participate in the nomination process of one party, are not permitted to participate in the nomination of other candidates, including independents.
Because of this, independent presidential candidates may not gather signatures until after the presidential primary. The end date is set at a specific date in May.
In 2012, the primary was delayed because neither the legislature nor the federal court was able to contrive a lawful redistricting map in time for the March primary.
When they finally did set a primary date in May, it was after the deadline for collecting signatures, so the court ordered a new date for the 2012 election.
The filing deadlines in statute for independent candidates and newly-qualifying parties are being used in 2014, and are not subject to 2012 order.
Though the redistricting lawsuits continue, I don’t think you can presume that will have any effect on future presidential elections.