They do "Get Lucky," Celebrate," "Harder, Better, Faster, Stronger", "One More Time" and then an awesome mashup of all of them at the end.
I found the blue eyes a little annoying at first but dang… their harmony totally won me over. Apparently, they are winners of the 3rd season of "The Sing-Off"; I've never seen it but after watching this I can see how they'd win.