As to today (June 4, 2013) the cast of characters:
BZelf & Bwix; Yvonne & Burt
C-Rad; Roger, Patti, Brianna (daughter) and Carly (daughter)
CanadianDISfan; Gabriella, Terry & Matthew
Disney Enabler & Merry Mousketeer; Carol & Michael
DisneyKevin & Webmaster John; Kevin & John
DisneySuzy; Sue, Bill, Amanda (daughter), Ben (son-in-law), Wanda (Mom) & Dean (Dad)
DSNYDREAMER; Tracey, Chris & Ben
Itsmuggsie; Muggsie, Cindy & Ellie (daughter)
LionKingRules84; Angela & Ryan
LuvsBlueDiamonds; Michele, Eric and Mikayla 11
Mikelan6 & ShellyMinnie; Mike & Shelly
msjuyamc; Kim
mskayo; Kay & Mike
myweegirls; Liz, Eric, Anna 8, Tessa 6
NewMouse: Teresa
NitroStitch; Lisa, but no Paul this trip
OKW Lover & OKW Lover Lover; Jeff & Val
Penny Mouse; Penny (first cruise) & Whitney (niece)
Princessclab;
rn4val; Debbie & Tina (SIL)
SafetyMom; Kathy
Shogo;
WDWworld; Bob & Julie
Webmaster Pete; Pete
WebmasterKathy; Kathy & (better half) Tom
Wimpy & DisneyFanInPA; Jim & Jayme
Total of 56 so far. In addition, Pete has said that nearly all the other Podcasters will be on board.