No on the Pirates cast, just people that did a good job, IMO. But true about Boxleitner for Tron (though as I'd seen B5 a heck of a lot more recently than Tron, the experience was... odd).

Oh, and avoid full cast lists until you're very near the end of the game as they contain spoilers. ;)

Here's a partial list with the VAs for the Tron and PotC worlds -

# Crispin Freeman ... as Setzer Gabbiani, Will Turner
# Corey Burton ... as Yen Sid, Shan Yu, Dale, The Peddler, Santa Claus, Sark, MCP
# James Arnold Taylor ... as Jack Sparrow, Timon
# Eliza Schneider ... as Elizabeth Swann
# Brian George ... as Captain Hector Barbossa
# Bruce Boxleitner ... as Tron