Xypherous said several times that IE/PD/BT is still the optimal item build (during their tests) because it's still the best way to get single target damage. There will probably be the Triforce ADs (Ez, Corki), the IE/PD ADs (Vayne, Trist), then the Hurricane ADs (Twitch, Varus). People who could use Hurricane will probably replace IE/PD in their build with Hurricane/BotRK. Triforce users may use that new Manamume item as well. This all assumes the new items actually turn out to be good.
I have yet to play Zed but Triforce is probably better. They say he's an AD assassin but we really know that means tanky DPS (Or bad).