I am an alchemist / herbalist, both at 225. I can confirm that I have neither lifeblood ability nor the mixology perk buff for elixirs and flasks. Oddly enough, my spell book still shows mixology passive, so I doubled checked by drinking an elixir of wisdom (normally gives +8 intellect, but with mixology gave +14 pre-patch). However, I only receive +8 intellect now, which means mixology perk is lost.
I assume now the majority of twinks will grab engineering as one of their professions without hesitation. The reason for this is for the toys and random gizmos that can mess with people. Think about bombs with stuns, for example. So much CC lost in warlords that those bombs, if used right, could be invaluable. Also, minor discombobulator, gnomish shrink Ray, parachute cloak, among others, are still very much useful.
As for the second profession, that might be more up to the player than anything. JC will give the healing statues, which are pretty nice. But I doubt some will drop their professions straight away. I bet lots of people invested time and money learning certain recipes and such. But definitely take a closer look at engineering, and possibly JC. I think I'll stick to Alchemy as one, but drop my herb for engineering.
Cheers!