The Windows Forms editor in Visual Studio is second to none. Visual Studio 2005 adds support for a lot more Toolbox items to populate your forms with. Back in 2002, Brian and I had to jump through some hoops to get the IE browser component embedded into BSNews. Now, there's an integrated Browser component, as well as the new MenuStrip, ToolStrip, and so many others. The previous versions Toolbox looks empty in comparison.
One of the new features is snap alignment. When you select a component on your form and move it around lines are drawn to help you make it line up with other items on the form. It's intelligent too, so if you have 3 text boxes above the one you're currently dealing with, it draws the lines such that you can match it with the others.