i tried your theory out on my 80 ranger a couple of days ago, using 4 x afflicted and 2 x krait, i then tested my bleeds on single target mobs, these runes did not effect my condition durations AT ALL. what was a 6 second bleed, remained a 6 second bleed, i didnt go by the tooltips, i went by the actual debuff icon on the target. it lasted the same wether i was wearing runes or not.
Traits seem to be working though as far as duration goes, it seems to be just the runes that arent.
i did the same test in both PVP and PVE on both my rogue and my ranger, same result, runes still not working for condition/bleed/poison duration.