Lots of developers are building XAML-based applications today. Be it WPF, Silverlight or Windows Phone 7, I have seen a lot of people struggle with certain tasks in Visual Studio that would be much easier if undertaken in Expression Blend. Blend seems to be somewhat intimidating to developers, especially those that are already wrestling with learning XAML. Having spent time in both tools, I can tell you that Blend can make three things dramatically easier, and you should learn how to do these three things with Blend, even if you never use it for anything else.
See the video on Channel 9.
Download Demo Code