I think you have simply to wait and be active in your intro thread (as you are doing actually) and be active around the public areas.
The approval process takes a minimum of 72 hours, and it can take up to a week (sometimes longer), usually depending on:
- your activity in your Intro Thread,
- your activity the other social areas of the forum
- the number of applicants
- how busy the staff and the approval teams are
So to sum it up, the approval proces takes from three days to a week and may take even longer.