The experience is very telling, and at the moment it's a no-brainer - iPhone, and it will reign for a long time yet. If you want to develop for Android you're probably better on custom apps / devices (tablets, specialized apps) as an employee rather than as an independent app developer.
The market demographics are very different - Android : 3/4 male, purchase apps 1/2 as often as iPhone users. iPhone users, around 50/50 male/female, affluent (as Android comes with cheaper devices the owners of those devices probably aren't using the platform the same way as iPhone users do).
Obsolete platform hardware/software - this is huge. Most existing Android phones won't ever get an upgrade to 2.x Android OS. Therefore to reach the market, you need to make it backwards compatible with the 1.x, which is a PITA.
Apple has only just announced that their next OS won't work on original iPhone (2G). This is a massive difference. You have been able to build for the latest OS for all iPhone devices for 3 years. Contrast this to Android - some devices released in the last 6-12 months won't run software built against latest Android OS.
Flash - this is big and I believe it will push prices lower in the Android app store. There has already been a "race to the bottom" in some categories (e.g. games, think 99c variety) in the iPhone App store. iPhone users will pay for games that you can play in a browser on a late-model Android phone for free. Therefore there's less incentive to pay for these games on Android devices.
Discoverability will always be a problem for any platform.