The NFL league office announced that they're changing the key free agency deadline of June 1st to May 12th. The now May12th/previously June 1st cutoff has salary cap implications -- players released by teams after that date can pro-rate signing bonus money into the next year in order to spread out cap hits. That date also has free agency implications, as veteran players signed after that date do not factor into the compensatory pick equation. So, for teams like Seattle that are sensitive to that formula, this move to May 12th is a nice little bonus.
This means that instead of waiting until June to finally sign any outstanding unrestricted free agents, teams can sign them after the Draft on the 12th, and that allows these free agents to get into offseason camps, into team programs, get their playbooks, etc, a few weeks early.
Look for a bevy of signings on that date, as NFL teams look to fill out their rosters after seeing how their draft haul turns out.