The NFL today informed teams that the 2015 salary cap will be slightly higher than originally projected:
NFL notified teams today that it expects this year's salary cap to be between $140 and $143 million, at least $1.5M higher than projected.— Adam Schefter (@AdamSchefter) February 18, 2015
This will of course help some teams who are cash strapped this year (I'm looking at you Miami Dolphins), but it is not a significant amount over the previous $138-$140 million projection. The Dolphins will still need to make some business decisions to free up salary cap space, especially if they want to be active at all during the free agency period this year, but the extra space is nice.
The new league year, when the new salary cap goes into effect and when free agency begins, is set for 4pm ET on March 10. The three-day "legal tampering" period will start on March 7, allowing teams to begin negotiations on contracts with players who will officially become free agents when the new league year begins.