Nearly doubling its selection over the past year, Android's library of market place apps has finally swollen to more than 50,000. While still only a quarter of the apps found in Apple's App store, 50,000 is a psychologically important number for Google and the credibility of its Android platform. The "Market" was made available on October 22nd of 2008, making it a year and a half old. By comparison, the iPhone's App Store took roughly one year to reach the same milestone.
If the Android Market can maintain its momentum, Google should amass about 100,000 apps by September. With the anticipation surrounding soon to be released Android-based devices such as the HTC Incredible and possibly even the Asus EEE tablet, momentum will most likely not be an issue.
As for the numbers, updates were not considered in the total apps reported. More detailed statistics can be found at AndroLib.