Path of Exile's upcoming Necropolis expansion is adding a support gem called "Sacred Wisps" and a unique that boosts the number you can have active. Grinding Gear Games had briefly mentioned this during last week's livestream, and have now clarified that they have reduced the number of wisps in favor of them each having more damage citing them wanting to avoid "performance issues".

The new wand boosts your elemental damages based on your physical damage, and also increases the number of wisps.

For the support gem side of it, Sacred Wisps supports skills that can be used with Wands, and not Vaal, Minion, Movement, or Totem Traps, and Mine skills.

Quote From Path of Exile

In 3.24, we're adding a new Support Gem, Sacred Wisps, and a new Unique Wand. We mentioned that Sacred Wisps would always trigger when a Rare/Unique enemy is nearby. To avoid performance issues, we've reduced their chance to trigger but have increased their damage to compensate.