Lion’s Whole-Disk Encryption talks about how to make other disks (besides startup) encrypted in Mac OS X 10.7 Lion.
Mail.app 5.2, the version on Mac OS X Lion (10.7), is disappointing. It works much better with Micro$oft Exchange than the old version, i.e. it doesn’t crash 20 times a day and that’s a good thing.
However, the search is very disappointing. The interface is neat with the new auto-tokenizing feature but, there doesn’t seem to be any support for boolean operators or nesting so it’s still about as useless as before.