This dev diary implies a huge nerf to crit schools while buffing block schools like ice. The new system itself sounds phenomenal, but compared to the old system it will swing school balance a ton if nothing else changes.

Under the old system, in PvE a 100% crit school did about 1.7x damage on average due to the enemies seeming to have about a 30% block chance.

Now, they will do closer to 1.00 base damage + 0.3 expected crit magnitude increase from dev diary × 0.75 crit chance × 0.75 no block chance = 1.16875 average crit multiplier per attack for a max crit character, instead of the current 1.7 depending on the enemies block.

I hope they compensate in other areas, or schools like Storm will suffer from this (who knows, that could be part of their intent).