iPad now has 30,000 Apps available, look at the data gathered by PadGadget and Apple App Store
Projecting this curve, the iPad should have 50,000 apps available by Christmas...and will likely hit the 100,000 mark by Labor Day next year. The iPad App store currently has the 3rd largest mobile apps platform, trailing the iPhone and Android. Three times as many iOS apps exist as compared to the Android.
PadGadget also has a nice iPad App Tracker, be sure to check it out!