I loaded up the game as Pate (OPM with wrong religion) and did some math.
The new monthly cost to reduce corruption at 1 corruption per year, is 0.05/development_adjusted_for_autonomy. It used to be 100% of your income. Since income is roughly 0.10/development, corruption costs have been reduced by 50% on average, and way more than that for countries with high trade income/gold mines.
I've seen Johan repeat that he wasn't willing to nerf corruption, so I hope this is not an oversight and that he actually changed his mind. The current situation is more interesting. Corruption is not completely crippling but now I'll have to think twice before I conquer land I can't convert or let my diplo tech tank.
I'd still rather see this mechanic removed altogether so they can add more interesting money sinks and incentives to increase diplo tech, but I feel like it's a step in the right direction.
Does your income factor in production as well as tax? 75% LA cap is still going to be a pain.