After bumping into difficulties with the system as first proposed, devs came up with some solutions to address concerns. The new system includes a new class of weapon that produces expendable effects (called spells for casters and maneuvers for non-casters) and alterations to the Refresh system. The expendables are also dropped as loot and treated like learned feats, which also prompted a few changes in active feats. You can read up on all the details in the blog post.
[Thanks to Crysillis for the tip]