Baby Blend Rant
Well not really a rant, more of a lamentation that Blend, like every other [web] designer before it, doesn't really understand the concept of dynamic layout.
WPF finally offers a VERY dynamic layout system, but blend, when you move things around still hard codes sizes and/or margins to make the dynamic containers (grids, dock panels, and stack panels especially) into very static entities... I'm getting tired of going through and telling it to "reset" the sizing information for everything.
But, at least it ALLOWS a way of resetting a value (i.e. choosing to not specify a property)