He could sign his contract today if Major League Baseball and the players' union settle their grievance. That would be great.
UPDATE: The grievance has been settled. Alvarez has been removed from the restricted list, and Eric Hosmer has been rescued from limbo status as well. The Pirates' contract with Alvarez can now go through. There may be a press conference tonight.
Also, now the deadline can't be extended unless both MLB and the union agree. Glad that's been cleared up.
UPDATE: There's a press conference at 6:00 PM. (Thanks to Uncle Nate.)
UPDATE: Alvarez has signed his contract. Tom Gorzelanny has been placed on the 60-day DL to clear roster space for Alvarez.