We hear from Paul Thurrott that Microsoft expects to have around 1000 apps available at the time of the US launch .
The information, which came via an email, notes:
The number of apps in the Windows Phone Marketplace continues to climb with more than 450 apps currently available and hundreds more going through certification as we speak. In fact, weâ€™re confident that that by U.S. availability Microsoft will have more than 1,000 applications and games available for download with several hundred more being added each week through 2010.
While 1000 is a far cry from 300,000 apps in the iPhone app store, the applications, such as the eBay app demoed above (via wpcentral), appear to be the key ones which means the selection should satisfy most early adopters.