The feature will start as invite-only, allowing public figures (in the beginning, only users with high subscriber counts will be invited) to change their account to verified status.
Once the account is verified, it will appear more frequently in the "people to subscribe to" list.
Twitter launched verified accounts back in 2009, and Google+ launched a similar feature shortly after launch.
However, unlike Twitter's version of this feature, Facebook won't display any sort of badge on verified accounts - a somewhat odd decision, since having a way to distinguish the real person from impostors is precisely why this feature is useful to most users.
Instead, verified users will have the option to display a nickname (Facebook normally requires all users to use their real name) instead of a real name, or have their real name places in parentheses.
To verify your account, you'll have to send Facebook an image of a government-issued photo ID, or a combination of two alternate IDs (such as birth certificate and credit card). While this will certainly make some users uneasy, Facebook promises to delete this data after verification.
Image courtesy of iStockphoto, Jirsak