I think I mis-read your statement as saying that 47% chance people are leaving BB for other platforms
We're both using very bad math to make the same point. I'm saying that if we can ignore any sort of brand loyalty, a random user who has left a smartphone for a Droid has a 40% chance of being a Blackberry user, a 25% chance of being an iPhone user, etc.
You're ignoring the longer lifetime of Blackberry phones (Blackberry users aren't as prone to chasing the latest shiny so they use their phones longer) and translating that 40% installed base into recurring sales figures.
What we're both saying, which is true, is that when you've got the majority of the market share you should expect a lot of people to migrate from that brand. I'd expect more people to move from Mercedes to Porsche than from Lamborghini to Porsche just because there are more of them, it doesn't mean that the numbers who switch are actually hurting either company's bottom line.
More interesting bad math:
Blackberry sales for the period had a 0.4/41.7=1% drop in total marketshare
Apple sales for the period were down 1.0/24.4=4% drop in total marketshare
Means absolutely nothing (especially since the latest numbers available predate the iPhone 4 and the latest roundup of Droids), but good schadenfreude to position Apple as losing marketshare 4x faster than RIM.
BTW: I also agree there's a lot of neat things I liked about my Storm that would be great on the Droid (rotate screen in any direction in just about any app, bulletproof bootstrapper (never been able to get a Blackberry to not load an OS), easier browser User Agent switching, better security features, etc.). Still, can't give up my new pwecious' pretty browser!
Lesson for others to learn:
Every phone is the best for someone's definition of best!