Paizo just released another blog post about rules changes for Pathfinder 2. In the blog post, they reveal a "new" idea that has been used in other non-D&D systems, and that has been proposed for 3.5 variants before. Each check, rather than being a success or failure, can be a critical success, success, failure, or critical failure. The blog post is sparse on details: they give a few examples of critical successes and failures for abilities that don't do damage, though without saying what the normal success condition would be. There is a bunch of grandiose language about how great the new system is going to be without getting bogged down by pesky things like how the new system actually works. On the flip side, in some cases Mark Seifter has given specifics in the thread in response to people's questions, making the thread slightly more informative than the actual blog.