Source points are one of the more interesting additions for me. It adds a tactical level of resource management that was partially stripped away by the AP changes. It also adds a strategic element that D:OS combat has generally lacked.
The big key in making it work will be toning down some of the standard skills a bit(this is needed for other reasons anyway) and really making spending those source points a critical decision. Once you do get vampirism it's trivialized a bit in between combats so it becomes too easy to walk around with a full source point stock.
