12:03am: Taillon's bonus is worth $6.5MM, according to Jim Callis of Baseball America (on Twitter).
9:14pm: Taillon and the Pirates agreed on a deal worth slightly more than $5MM, according to Jon Heyman of SI.com (on Twitter).
7:52pm: The Pirates signed second-overall pick Jameson Taillon, the pitcher's father told to Chuck Finder of the Pittsburgh Post-Gazette. The tall Texas right-hander has drawn comparisons to other power pitchers such as Roger Clemens and Josh Beckett. Back in May, MLBTR's Mike Axisa profiled Taillon in detail.
The specifics on Taillon's deal aren't yet known, but MLB recommended a $3.25MM bonus for the second overall pick last year. The Mariners, who chose second overall in 2009, signed Dustin Ackley to a $6MM bonus and it wouldn't be surprising to see the Pirates pay Taillon considerably more than slot, too. They already appear to have signed second-rounder Stetson Allie.
With less than three hours remaining between now and the deadline to sign picks, 13 first-rounders have yet to sign.