My tablet is rooted so I managed to move many apps to the internal SD card with "Titanium Backup Pro".
I guess when I get an external SD card I would need to use your method to move apps there.
Here are some other apps that might help:
DS Super App2SD Lite
this one can move more apps with root access and can be set to install downloaded apps directly to SD card!
Convert External SD to Internal SD Android (Specially For Low Budget Devices)
How to REALLY put apps on external sd card android
DirectoryBind - move data to external_sd http://forum.xda-developers.com/show....php?t=1410262