Could it be possible for WinMo, Palm, Android and Blackberry to cracked a 500 million downloads like the iPhone Apple Store?

Just today, I came across these mobile news stating that iPhone App Store has served 500 million Downloads. Big chances are for those iPhone and iPod users as there more than 15,000 Apps on the App Store.

There are of course lots of free Apps that users download, where Apple does not make money from, but there are still enough Apps that generate a nice revenue for Apple if the downloads continue to grow in this fast pace.