Nope, last update changed that, yes you can still cache but with the latest version you can actualy save the entire map that you are looking at including all zoom levels bellow that to your phone.
Simply press menu and then save for offline.
Alternatively if youwant a completely offline solution, NavFree is your best bet. 13mb market download and about 200mb for the latest sa maps. Updates the maps every 2 months, part of one of those open source map groups. Includes voice navigation.