I have 200+ paid apps on Android and yet the only app I care about for a potential migration is a free one called Google Voice. I don't mind buying redundant apps for a different platform. I figure the usual under $5 cost per app should go to support poor developers... (*cough, I might be biased...)if you have a ton of apps (legitimately paid for) then it's going to be extremely difficult to migrate from iOS (or to iOS). I'm not sure why these discussions ignore that part of the equation.
But I need Google Voice to work well in order for me to go WP7. I have given out that number to too many women. Maybe I just need to develop it myself... but I'm getting too lazy.