I thought that's what it was referring to at first, but that trait appears to refer to the dual skills.
http://wiki.guildwars2.com/wiki/Combo_Crit_Chance
Look at where "combo skills" links to. You're thinking of "chain attacks" I guess.
---------- Post added 2012-04-19 at 12:50 AM ----------
Now if only I could decide whether to keep the 20 points in Shadow Arts, or to move them down to Trickery...
Thrill of the Crime/Bountiful Theft and Initial Strike look good... But doing so means I no longer get to have "perma" stealth...
I'll have to test whether or not I actually care about perma-stealth.
I also need to test whether to use Combined Training or Sundering Strikes... or even if I should try to move 10 points there to ADD Sundering Strikes...
Oh the madness these builds will cause! @.@