So the number of BA`s on future badges is good idea I think...
And you can see this number currently - it's a very good way to gauge how over-and-above qualified the user is in their field of expertise.
Once I got my gold I didn't move to other sections as owning a Laptop repair company, it was where I was best suited to give advice....
This is generally the case. Users who get acclimated to a given section build up a reputation as a good source of information on subjects, and most stick around. Even in the previous version of the forum where the highest you could go was Gold, most Gold level users remained highly active in their areas, and the badges were meant as a ready sign of trust. This really is the goal of the badges system, to not only reward and incentivize answers, but also to provide users asking for help a quick way of determining if the answers provided are coming from solid experts.
I assembled an FAQ on badges, and some of the transitional issues you guys have asked questions on. Please be sure to reference this first if you have any questions, and feel free to refer other users to it as well who might be uncertain about some of the changes. http://www.tomshardware.com/forum/id-1631966/badges-reputation-faq.html