No, not a scam. It was really the Facebook Team asking for identity confirmation. They want to be certain that the demographic info they gather can be cross-referenced to an ongoing database that collects info from browsers and website cookies and such.
I might look into the other FB options, but I have to decide if I want to play FB again. It takes a lot of work staying involved and dealing with the "opinions" one can encounter in discussion groups. Facebook is becoming a legal liability. If someone can be certain that the FB profile is really you, it can be used in legal proceedings, by collectors, employers, the IRS and other more clandestine government agencies in this country and abroad. By asking for identity confirmation, FB could be placing people at risk.
Greed is the only reason Facebook will not allow the uncomplicated use of screen names or web identities. Forgive me if I do not trust in Facebook's reassurance that my information will be kept private or will be deleted after my identity is verified. The operators of this particular social media have not been honest in the past and show no signs of being honest or truthful in the future.
Remember MySpace? With their overbearing presence, it won't be long before the question asked will be: Remember Facebook?