There are some powerful pvp sorcs that have maxed End... it's a playstyle thing more than anything.
Do what feels right, anything is viable in this game (as long as you're playing with class-relevant stats and figures).
DPS Sorcs or Heal Sorcs?
I find it hard to imagine any heal spec being effective with maxxed endurance. Well, dps too for that matter. Heck, as a healing sage, the increase on my free self heal (with high willpower) outweighs the hp increase (with high endurance), let alone the increase of my other heals.
Seems wrong to me.