We are definitely going to get a buff in 8.1 due to the projected damage output expected with higher gear levels, enhancement does not look to be scaling well.
http://simulationcraft.org/reports/T22_Raid.html
You are correct, in order to beat a demon hunter on a boss fight he would either need to be targetted by the boss more often with cc abilities or have about 5 ilvls lower then us. Even playing enhancement close to perfection we are just not going to beat any Demon hunters who know how to play their class above average.
Same with Windwalker monks, rogues with similar ilvls.
I am levelling a windwalker atm (lvl 114) and I am totally destroying the other dps in dungeons, WW are very powerful atm.
However I have found we have 1 big arsenal up our sleeves and that is the earth elemental, it has saved our group from trash wipes on a few occasions and on boss fights when the tank dies and we have like 15% to go. So while we not going to be the top dps, some groups like to have us because of group stun, earth elemental and 12s cd on interupts.