If you decide to pass on this and opt for straight regen trinkets and this drops for you, it might be worth hanging onto. It is the only trinket in 5.2 for healers that will scale with SP and therefore benefit you more as you gear.
It also might be more beneficial to those classes with very few smart heals as this trinket gives you a (passive) smart heal.
•Lightning-Imbued Chalice now has a greatly increased chance to generate Infinite Power.
Not sure what greatly increased chance is in RPPM, but it should be better now!
This trinket is one of my favorites as it procs with every heal spell, including HoTs. So, e.g. Shamans, can lay down a Healing Rain and each tick on each person has a chance to proc the trinket; combined with Earth-living/Riptide/Chain Heal/Healing totems and you have non-stop procs.
Also procs for Atonement heals.
Sorry if this is overly obvious, but you need to be in combat for the trinket to work. So melee a target dummy and then start spamming heals.