A nice summary post on the use of the product is up at Emergency Medicine PharmD. Full prescribing info on the product (Kcentra) is here.
Another post at the same blog has some background information. According to that post high level data are lacking about what's really the best agent for warfarin reversal though four factor PCC has at least theoretical advantages. Don't forget, too, that the ACCP guidelines now recommend it over other agents for reversal. My guess is that it is expensive and will be the topic of P&T committee discussions across the country in the coming weeks.