While the interface changes in Mac OS X Lion are confusing, the whole-disk encryption provided by FileVault is a definite step forward.
People who have their laptops stolen and then find their confidential documents posted all over the internet really have no excuse. If it is sensitive, it should be encrypted – especially if it is on a portable device that cannot be wiped remotely.
I hope a future release of iOS includes comparable whole-disk encryption capabilities. iPhones and iPads are even easier to lose than laptops.