Fundamentally, protecting data is a matter of setting and enforcing appropriate policies. By itself, disk encryption won’t protect data on laptops. That’s why you should consider carefully what kinds of data your organization is willing to allow to be put on laptops in the first place. Next, you should set policies and standards to help protect the data you do decide to allow on laptops. But, that said, whole-disk encryption of laptops is a major step forward in preventing misuse of data on stolen laptops.
Not to mention helping you sleep better at night, and significantly reducing corporate consumption of antacids.