I had noticed that the drop-down to choose who gets what split (Devs/Publishers, Charity, and a tip to Humble Bundle themselves) goes where was missing recently, but I assumed it was probably a bug that they'd introduced in their coding that perhaps didn't like certain browsers.
Today I had a bundle with the drop-down, however instead of 'Choose' it now says 'See', with no ability to choose how much goes where.
Once again, I thought perhaps it was buggy coding on their part, but as a check in another browser showed exactly the same issue, I did a quick search.
A result quickly came up from a couple of days ago, from HEXUS' sister site bit-tech.
It seems IGN's purchase of them has finally taken effect, as it's severely reduced the main reason I liked purchasing via Humble Bundle, by limiting Charity splits to 15% at most - and that's if you specifically select the 'Extra to Charity' option, otherwise it will default to 5%!
Understandable on a Humble Store purchase perhaps, but a huge change to the behaviour on the Bundles themselves.