(1) I have no idea what to expect with the Cata talent guide.
(2) I removed all the old "talented.lua"
(3) I used the "all-in-one" installer.
There is no addon I can find to click "on." The behavior of the talent selection is just native WoW.
The talented guide is in the Blizzard's Talent UI. When you open your talent UI, you will have 2 tabs at the bottom of that window. (3 if your a hunter and have your pet out). One will say Talents, the other will say Talented.
Talented is the one you want. From there, select a template, then in the Action button, you want "Set as Target". Then go back to the Talents tab and voila.