you really shouldn't change categories once the competition has started.
For example I haven't added my apps to list, since I'm waiting for the real submission page to open before doing so.
Developer Application Category Current Progress (%) Beginner Entry (Y/N) S.Elop " " Location and Navigation "" N
I just don't want to see 100 pages of "what if / unfair rule changes etc."-emails which could appear after the competition voting has ended.