The charm will only be sold by one carrier as that carrier has exclusivitey on it. I think the charm will have a valid business and "prosumer" niche. I think executive will like it as it looks more like a phone. Better than putting a "brick" to your ear as I've heard it said. I love my BB but I really think I will want to switch to the charm when it comes out. I is pretty cool.
As far as camera and mp3 players on a Blackberry. RIM has not only said no but "hell no" time and time again. The Blackberry is a corporated device and as such they are building it for corporate use and RIM sees no corporate use for cameras or mp3 players. If you want that, then get a crappy treo.