Per multiple people on Twitter, the Memo of Understanding has been completed and signed by both the players and the owners. The owners ratified the CBA on Wednesday, and the players ratified the CBA this morning. The MOU was the piece of documentation required to allow the lockout to be lifted and to allow business as usual.
With the MOU signed, training camp can begin, schedules can be released, trades can happen, teams can sign players, and waivers are now active. Welcome back to hockey.