Yes I do not expect a huge amount of widgets right from the beginning but if there are thousands of apps, in theory evey developer can develop a home screen widget for its app. So assuming every app offers a home screen widget and we have 1000 apps to start then you have 1000 widgets just like that.
Again, all this in theory.
In the other hand Nokia will offer many high demand widgets from day one.
Weather, Stocks, News, Facebook, Contacts, Apps, Calendar, Email and Ovi Store Widgets, will satisfy most of the people.