The new amulets will allow players to take better advantage of their secondary school choice attacks. As a result, each wizard will pick an amulet, hopefully based on what their secondary school is that best fits their playing style. So it is too difficult to say which will be least played given each individual wizards set up. Some will work better than others, of course.
Although I do know of a few spells that people would love to cast for less pip cost:
Earthquake Judgement (treasure most likely) Heckhound (Oh my goodness...) Pixie and Satyr (Now I can finally heal and not lose all of my pips)
I made a horrible mistake and bought a balance amulet. I should have taken death along with my life amulet to accompany for some future choices. Ah well.
Aren't the school quests spells that make the schools special in the first place?
I can foresee a lot of ice/life, ice/storm, life/death and maybe life/myth combos. Life because myth has two AoE spells where as life has none until the level 58. Balance/life would be a really good support wizard.
Most unlikely attack based wizards will probably stick with life as a secondary for satyr. But, if they want to stick elemental/elemental or spiritual/spiritual so that they don't have to carry extra blades their primary school can't use.