While I've found some solutions to the problems reported on the following forum threads, I think it's scandalous and worthy of AI to report and to ask questions of Wacom regarding this matter.
Here is a quote from a moderator on their forum:
It seems that the needed information has not been added to the public FAQ...
Use the Android File Transfer tool in the "Wacom Tablet" folder. It is used similar to the Finder.
By default Android devices cannot be accessed as USB drive from OS X. The manufacturer of the device needs to specifically alter Android to allow this.
Since Wacom uses a mostly unaltered standard Android, it is needed to use the free Android File Transfer software from Google (http://www.android.com/filetransfer/) to access the files on OS X
My posts on the topic:
German Installation Applications ->Wacom:
Android File Transfer
Wacom Desktop Center (duh
Wacom Display Settings