Change Mount Point for SD Card?
As eldarerathis noted in his comment, this will require root. But you don't need to manually edit the vold.fstab file for this, as there are some nice little helpers available:

Root External 2 Internal SD can swap your cards (i.e. exchange their mount points):


Root External 2 Internal SD (Source: Google Play)

Note that this app requires Android 4.0 or higher.