It’s hard to compare Apples to Androids, but we do it very often nonetheless. In this case, we are looking at app distribution.
The Apple App Store has about 250,000 apps, and nearly 70% cost money, while 30% are free. The Android Market has about 100,000 apps, and is reversed; 35% paid and 65% free. 148apps.biz reports that there are about 630 new apps in the App Store daily, compared with about 590 per day last month on Android. There is no hard and fast reason behind this discrepancy, but some have speculated that Android developers are more likely to be hobbyists as there is no stringent approval process to get in to the Android Market. Further, since Android is a (mostly) open-source system, a lot of the developers may come from an open-source background and are used to giving away their work. Another thought is that the Android Market only supports purchases in 13 markets while the App Store does so in 90.
Most of the other stats are hard to compare because people are looking at different information for the two stores. It is interesting to note that the more popular an app is in the Market, the more likely it is to be free. For example of the 838 apps that have been downloaded more than 250,000 times, only one of them is a pay app.
If you want to check out some statistics and graphs about the Android Market, go to AndroLib.