Facebook's recent changes make the broadcast of beacon-collected newsfeed items opt-in on a per-story basis. However:

1. Facebook should provide a universal opt-out. (fixed Dec 5th, Danke Facebook)
2. If Facebook wants to know what movies tickets I'm buying on Fandango (to name one partner), it is the responsibility of both Facebook and their partners to ask me if its OK for them to share this information. This makes me wonder who else beacon partners are willing to share my information with. Read more about this here.

I can see how something like beacon could provide value for users, advertisers, and network operators, but until it is implemented in a more thoughtful way, I'll choose de-beacon.