As long as Reincarnation is off the shared limit with other brez it will still be a great part of the shaman kit.
There's always going to be a cost to it because of that (low mana/hp). I can understand why ele and resto would be pissed at the mana though. You get around being gibbed again by being smart about your timing and communicating with healers...seriously not that hard. And if for some reason you have to do it instantly with damage doing out and no time to communicate then pray you've got a healthstone to use
the moment battle rezz is touched by blizzard will be the moment where it may get nerfed or removed. if they make it stronger it can't be off from battle rezz anymore.
lowered cd would be nice and increased healt/mana, yes of course.
the only thing that would work is a glyph that incrfeases the health/mana but also increases the cd as compensation. would fit into their "get profit for some drawback" style of shaman glyphs.
for me ankh is not useless. it may is useless in some moments when you died in some fire or where you have constant aoe dmg. so simply standing up will kill you instantly. so you have to prepare for that. drink some potion, use health stone get some instant heal.
but it is a great way to bring you back into the fight. resto may struggle more due the mana issue but ele and enhancer can do pretty good after ankh very quickly again.