What have been some of the most helpful resources for learning Blend from a developers perspective?
I suspect in the end we will hand off the XAML of our app to a design expert, but until that blessed day there are some things even a coding grunt should be able to manage in Blend that are painful in Visual Studio (styles for example)
Have you checked out the Microsoft training site? There is also lynda.com which has some free training to make use of. Overtime I have found the videos to the most rewarding, as walking through static screenshots is not very beneficial. Especially when attempting to understand the layout of Blend and making use of the varying tools within the product.
In addition, since you mention Silverlight, Tim Heuer has a blog which covers Silverlight and at times touches on Expression Blend. There is also Jesse Liberty who has since moved into WP7 to some degree but has varying tutorials on his web site which again touch on Blend to some degree. Both Tim and Jesse work for Microsoft so they can often times provide insightful information and are fairly active within the community in getting questions answered.