According to Distimo, the number of free Android apps outnumber free iOS apps 134,342 to 121,845. However, I think that statistic is misleading.
A quick search of the term "hello world" on the iOS App Store returns 4 free results, most of which seem to have a useful purpose. A similar search on the Android Marketplace returns 76 free results with many descriptions such as "just making this app to try out the marketplace" and "this is my Hello World application to test publishing to the Android Market." Others descriptions aren't so obvious but, based on screenshots, are clearly just apps that display a hello world message on the phone. This is, of course, usually the first thing a beginner's book on Android programming shows you how to do.
A search for "test app" on the Android Marketplace revealed too many results (2226) to try and tally but I was able to find a few examples of useless apps within just the first couple hundred. I could try and concoct other terms to identify similar types of apps, but you probably get the idea.
Obviously, this is not a problem for the iOS App Store since Apple wouldn't allow these types of apps to be made available. I'll leave it as an exercise to the reader whether this is a good or bad thing :)
At any rate, it's pretty clear that the Android Marketplace app count metric is much less meaningful than the iOS App Store one.