CLU sent the page to Alan Bradley from Flynn's Arcade.
>Kevin Flynn has been trapped in the Grid for 20 years, which equals to 100 years there.
>Flynn's identity disc has a program that'd allow CLU and his army to come to the real world and enslave the human race. The disc is the movie's McGuffin.
>Rinzler, CLU's second-in-command, is an enslaved Tron. He regains control in the third act and his fate is left ambiguous.
>Castor, the David Bowie-esque program, betrays Sam and is killed by CLU.
>Quorra is a living program, that is not created by a User. She comes to the real world with Sam in the ending.
>Kevin Flynn dies.
>Cillian Murphy has an uncredited cameo as Ed Dillinger's son, setting him up as a potential villain in a potential sequel.