According to German research group research2guidance, The Android Marketplace could surpass Apple's App Store in size this year. As TechCrunch points out, another analytics company, Distimo, paints a similar picture. The research groups assume that the current growth rates of both markets remain the same. If so the crossover date will happen sometime this August when both app stores hit 425,000 available apps.
However, the store with the most apps doesn't necessarily translate into the store with the most download