MyPearl,
I had read a lot of posts on here about people trying to clean these things as well as some folks complaining that their trackball only scrolled in one direction or the other so in my sunday boredom i decided to pull it apart. I've had my unit for about 3 months now and it was functioning perfectly and the parts inside were fairly clean but i can see that over time it will be an issue as there are some really good spots for dirt to collect in the moving parts. We all still have warranty on our pearls so if you have a problem with the trackball during the warranty period I would simply send it in for replacement. I hope that the entire mechanism will be available as a replacement part at some point for a nominal fee.
To answer your questions,
1) how often do we need to perform this operation? 6 mo, 1 yr?
Hard to say but I think you'll notice a performance degradation if it gets too dirty.
2) what is blackberry's aftermarket model for peforming this maintenance?
I have no idea
3) how much would you charge ?
I wouldn't be interested in doing other peoples phones. The entire job only takes about 10mins once you know how it works so i would hope that service departments won't rape people for this service but againxxx8230; think warranty while you have it.