Well, WPF is far more like learning the MFC libraries then the pure fun of VB past. That said, the leaning curve is hard. Big difference is seen when using Blend however. It makes the monster of WPF and the XAML all go away.
The XAML is nearly unlearnable to folks like me who refuse to use a product based on route memory. The is no feeback or help in VS2010 to know what should go where and what it's scope of effects may be. Clearly we are supposed to by Blend to make any "modern" faced apps.