According to Windows Phone Applist, who track various statistics about Windows Phone development, there are currently just over 30,000 apps in the Windows Phone 7 Marketplace.
The site also tracks the number of approved Windows Phone developers. Based on those figures, the influx of WebOS developers Microsoft is hoping for hasn't happened yet.
If Windows Phone is going to become a serious contender to be a third major player in the smartphone market, the next several months will be critical. Microsoft is counting on the upcoming Mango Update to Windows Phone and their partnership with Nokia to provide a sales boost.
There is a fair degree of uncertainty and lots of room for growth left in the smartphone market. Smartphone sales are increasing while former market giants are losing their share.
Nokia has been one of the biggest casualties, eventually leading to their alliance with Microsoft.
The question is whether Microsoft and their vendors can make a case there's an advantage to choosing an option other than Android or iPhone. Hopefully they have something stronger to open with than 30,000 apps.