Kudos for seeking user feedback on this product. While I'm late in replying (just discovered the forum), I'd still like to chime in with my 2 cents.
I'd love to see a rubberized (silicone?) case for the 8100 (transparent or black) that includes access to all soft-keys and ports on the sides of the device (including the lanyard anchor). And, although I'm not going to be playing catch with my Pearl, I'd give bonus points if you had thick, raised bumpers along the edges to give it some extra protection and grip.
Most importantly, I think it should have some sort of hard screen protector that is RAISED (up and off the surface of the screen) so as to prevent directly scratching the gorgeous screen, or indirectly scratching the screen by trapping dust right up against it.
Thanks, and I'm looking forward to seeing (and using) the finished product.