At level 80 you get an emblem for every boss you down, and after doing the first random heroic, you get 2 additional emblems for every instance complete.
No 29's are not "dead". The migration rumor is being spread by 39's who want the 29 group to migrate to their bracket. 29's experience 2v2,3v3,5v5 and WSG games.
Its all in the grand scheme of rash-partially thought out plans of the blizzard developers. Watch out, I might throw in a conspiracy theory soon about how blizzard is really the man and we need to stick it too them!