These are the differences:
- Is it possible to apply a style to all elements in your application?
Unforunately, the Beta 2 does not support implicit styles using the TargetType attribute like WPF. To apply a style to all elements you must explicitly set a value to each Style property.
- Is it possible to extend a style?
In Silverlight styles cannot be based on other styles. In WPF that is possible using the BasedOn attribute
- Is it possible to change the style of a control more than once?
No. Styles can be set only once in Silverlight in XAML or in code. After applying a style it is possible to change individual control properties though. You can affect the appearance of a control by changing the Template property and you can do that as many times as you want.
That's it!