[This question came up recently on an internal DL so I thought I would elaborate]

On the Visual Studio 2005 Product Feature Comparison Chart, you'll notice that the User Experience row lists Visual Studio Express as having "simplified menus and options". What exactly does that mean?

The goal of Express is to create an easy-to-use, fun, and easy-to-learn product for beginners, hobbyists, and students. One of the key challenges we wanted to address was the ability to distribute Express online as the primary distribution vehicle. That meant starting at the multi-gigabyte version of Visual Studio .NET 2003 and removing features to meet an IDE goal of just 30MB. We used the "less is more" principle in two ways

Removing features
The overarching thinking here is that if it can be removed, it should be removed, and the need to evaluate the feature for the audience. There was/is a lot of healthy discussion about what are the right features to remove for Express, but based on the feedback so far, we've provided a core development experience that addressed our customers needs. 

Simplifying defaults
While professional and enterprise developers want/require every IDE feature exposed, beginners and hobbyists are easily overwhelmed my the huge number of features in Visual Studio Express. To give an example, if you want to build or deploy an application you should have three options, not 12. Visual Studio Express includes the ability to create custom profiles that enable you add or hide menu options, toolbars and more. Below are screenshots comparing Visual Basic Express and Visual Studio Team System menus so you can see the difference:

Category VB Express Team System
Build Menu
Tools Menu
Breakpoint
Options
Add New Item

In another blog post, I'll show how you can fully customize your experience and even export your settings amongst multiple computers or say a teacher setting profiles for 30 students.