Good point about Mark, too. Not only he does a lot of voice acting, but he often does that for games. Even if we exclude the "Wing Commander" series from the list, the other titles would be such big selling hits such as "Call of Duty 2", "Soldier of Fortune 2" or "Icewind Dale - Heart of Winter".
Another actor who graced "Monopoly Star Wars" game was Anthony Daniels... speaking of which... the whole concept - weird as it may be - could be used better. Vader buying hotels? ...on Hoth? C'mon! I'd rather play Lando character instead, competing with other "shady businessmen" from Star Wars universe: smugglers, Hutts... Chance cards could include events such as "Imperial blockade" or "you have been caught with contraband onboard". "Go-to-jail" should be replaced by "Imperial Detention Center" etc. Oh nevermind...
After all, what am I talking about? If radio dramas had completely different cast... why treat the games seriously then... ehh...
And I'd still claim that the investment in those names would nicely pay off as promotional effect - more people would buy a game featuring a real SW-movie star, even be it only as a voice-over.
EDIT: Oh, should I mention that "Monopoly Star Wars" was released by... Hasbro?