To paraphrase:

BlackBerry Device Software 4.2.0 Up to 2GB
BlackBerry Device Software 4.2.1 Up to 4GB
BlackBerry Device Software 4.2.2 Up to 4GB
BlackBerry Device Software 4.3.0 Up to 8GB

This is actually what I've experienced and found from other posts. However, I haven't gotten to try an 8Gb in any 4.3 device yet.

Nice find!